Sinusitis: From Microbiology To Management (Infectious Disease and Therapy)

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Sinusitis From Microbiology to Management

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INFECTIOUS DISEASE AND THERAPY Series Editor

Burke A. Cunha Winthrop-University Hospital Mineola, and State University of New York School of Medicine Stony Brook, New York

1. Parasitic Infections in the Compromised Host, edited by Peter D. Walzer and Robert M. Genta 2. Nucleic Acid and Monoclonal Antibody Probes: Applications in Diagnostic Methodology, edited by Bala Swaminathan and Gyan Prakash 3. Opportunistic Infections in Patients with the Acquired Immunodeficiency Syndrome, edited by Gifford Leoung and John Mills 4. Acyclovir Therapy for Herpesvirus Infections, edited by David A. Baker 5. The New Generation of Quinolones, edited by Clifford Siporin, Carl L. Heifetz, and John M. Domagala 6. Methicillin-Resistant Staphylococcus aureus: Clinical Management and Laboratory Aspects, edited by Mary T. Cafferkey 7. Hepatitis B Vaccines in Clinical Practice, edited by Ronald W. Ellis 8. The New Macrolides, Azalides, and Streptogramins: Pharmacology and Clinical Applications, edited by Harold C. Neu, Lowell S. Young, and Stephen H. Zinner 9. Antimicrobial Therapy in the Elderly Patient, edited by Thomas T. Yoshikawa and Dean C. Norman 10. Viral Infections of the Gastrointestinal Tract: Second Edition, Revised and Expanded, edited by Albert Z. Kapikian 11. Development and Clinical Uses of Haemophilus b Conjugate Vaccines, edited by Ronald W. Ellis and Dan M. Granoff 12. Pseudomonas aeruginosa Infections and Treatment, edited by Aldona L. Baltch and Raymond P. Smith

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13. Herpesvirus Infections, edited by Ronald Glaser and James F. Jones 14. Chronic Fatigue Syndrome, edited by Stephen E. Straus 15. Immunotherapy of Infections, edited by K. Noel Masihi 16. Diagnosis and Management of Bone Infections, edited by Luis E. Jauregui 17. Drug Transport in Antimicrobial and Anticancer Chemotherapy, edited by Nafsika H. Georgopapadakou 18. New Macrolides, Azalides, and Streptogramins in Clinical Practice, edited by Harold C. Neu, Lowell S. Young, Stephen H. Zinner, and Jacques F. Acar 19. Novel Therapeutic Strategies in the Treatment of Sepsis, edited by David C. Morrison and John L. Ryan 20. Catheter-Related Infections, edited by Harald Seifert, Bernd Jansen, and Barry M. Farr 21. Expanding Indications for the New Macrolides, Azalides, and Streptogramins, edited by Stephen H. Zinner, Lowell S. Young, Jacques F. Acar, and Harold C. Neu 22. Infectious Diseases in Critical Care Medicine, edited by Burke A. Cunha 23. New Considerations for Macrolides, Azalides, Streptogramins, and Ketolides, edited by Stephen H. Zinner, Lowell S. Young, Jacques F. Acar, and Carmen Ortiz-Neu 24. Tickborne Infectious Diseases: Diagnosis and Management, edited by Burke A. Cunha 25. Protease Inhibitors in AIDS Therapy, edited by Richard C. Ogden and Charles W. Flexner 26. Laboratory Diagnosis of Bacterial Infections, edited by Nevio Cimolai 27. Chemokine Receptors and AIDS, edited by Thomas R. O’Brien 28. Antimicrobial Pharmacodynamics in Theory and Clinical Practice, edited by Charles H. Nightingale, Takeo Murakawa, and Paul G. Ambrose 29. Pediatric Anaerobic Infections: Diagnosis and Management, Third Edition, Revised and Expanded, Itzhak Brook

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30. Viral Infections and Treatment, edited by Helga Ruebsamen-Waigmann, Karl Deres, Guy Hewlett, and Reinhold Welker 31. Community-Aquired Respiratory Infections, edited by Charles H. Nightingale, Paul G. Ambrose, and Thomas M. File 32. Catheter-Related Infections: Second Edition, Harald Seifert, Bernd Jansen and Barry Farr 33. Antibiotic Optimization: Concepts and Strategies in Clinical Practice (PBK), edited by Robert C. Owens, Jr., Charles H. Nightingale and Paul G. Ambrose 34. Fungal Infections in the Immunocompromised Patient, edited by John R. Wingard and Elias J. Anaissie 35. Sinusitis: From Microbiology to Management, edited by Itzhak Brook 36. Herpes Simplex Viruses, edited by Marie Studahl, Paola Cinque and Tomas Bergström 37. Antiviral Agents, Vaccines, and Immunotherapies, Stephen K. Tyring

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Sinusitis From Microbiology to Management

edited by

Itzhak Brook Georgetown University School of Medicine Washington, D.C., U.S.A.

New York London

DK3789_Discl.fm Page 1 Wednesday, August 3, 2005 8:27 AM

Published in 2006 by Taylor & Francis Group 270 Madison Avenue New York, NY 10016 © 2006 by Taylor & Francis Group, LLC No claim to original U.S. Government works Printed in the United States of America on acid-free paper 10 9 8 7 6 5 4 3 2 1 International Standard Book Number-10: 0-8247-2948-X (Hardcover) International Standard Book Number-13: 978-0-8247-2948-6 (Hardcover) This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC) 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe.

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Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com Taylor & Francis Group is the Academic Division of T&F Informa plc.

This book is dedicated to my wife, Joyce, and my children, Dafna, Tamar, Yoni, and Sara

Preface

Upper respiratory tract infections and, especially, sinusitis are frequently encountered in the day-to-day practice of infectious disease specialists, allergists, pediatricians, otolaryngologists, internists, and family practitioners. The range of causative agents and available therapies and the constantly changing spectrum of antibiotic resistance can make it difﬁcult to select the most appropriate course of treatment. Given the increasing global concerns regarding the scale of worldwide bacterial resistance, which is largely because of the misuse and overuse of antibiotics, information that can enable physicians to optimize management of infections such as sinusitis will be of great value. This book provides state-of-the-art information on management of sinusitis tailored to the clinicians and health care providers of varied specialties. It contains a liberal number of ﬁgures and tables that clarify the underlying concepts and illustrate speciﬁc details. The authors selected to contribute to the book are the world experts and leaders in the topic(s) they address. The book opens with a comprehensive overview of the epidemiology, clinical presentation, and diagnostic techniques of sinusitis. It then delves into the pathophysiology and the microbiology underlying the condition. The next section of the book addresses the medical management of acute and chronic sinusitis as well as the comorbid medical symptoms. We then conclude with the surgical management of these conditions and their complications. It is our hope that this book will be a useful tool and an important resource for clinicians in the management of sinusitis. Itzhak Brook, M.D., M.Sc.

v

Contents

Preface . . . . v Contributors . . . . xv SECTION I. EPIDEMIOLOGY, PRESENTATION AND DIAGNOSIS 1. Sinusitis: Epidemiology . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Thomas M. File Jr. Introduction . . . . 1 Prevalence and Burden of Disease . . . . 2 Epidemiology and Risk Factors . . . . 5 Pathogens of Bacterial Sinusitis . . . . 10 Sinusitis and HIV . . . . 11 Nosocomial Sinusitis . . . . 12 References . . . . 13 2. Classiﬁcation of Rhinosinusitis . . . . . . . . . . . . . . . . . . . . Peter A. R. Clement Introduction . . . . 15 Classiﬁcations of Sinusitis . . . . 17 The Classiﬁcation of Fungal Sinusitis . . . . 28 The Classiﬁcation of Pediatric Rhinosinusitis . . . . 32 References . . . . 34 vii

15

viii

Contents

3. Rhinosinusitis: Clinical Presentation and Diagnosis . . . . . . 39 Michael S. Benninger and Joshua Gottschall Introduction . . . . 39 Deﬁnitions . . . . 40 Pathophysiology . . . . 41 Rhinosinusitis or Upper Respiratory Tract Infection? . . . . 42 Diagnosis of Rhinosinusitis . . . . 43 Conclusion . . . . 52 References . . . . 52 4. Imaging Sinusitis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Naﬁ Aygun, Ovsev Uzunes, and S. James Zinreich Introduction . . . . 55 Available Imaging Modalities . . . . 55 Anatomy . . . . 60 Imaging Rhinosinusitis . . . . 71 Presurgical Imaging Evaluation . . . . 84 Postsurgical Imaging Evaluation . . . . 87 Surgical Complications . . . . 87 Computer-Aided Surgery . . . . 89 References . . . . 89

55

SECTION II. ANATOMY AND PATHOPHYSIOLOGY 5. Anatomy and Physiology of the Paranasal Sinuses John H. Krouse and Robert J. Stachler Introduction . . . . 95 Embryology of the Nose and Paranasal Sinuses . Anatomy of the Nose and Paranasal Sinuses . . . Physiology of the Nose and Paranasal Sinuses . . Conclusion . . . . 108 References . . . . 108

......

95

. . . 96 . 100 . . 106

6. Pathophysiology of Sinusitis . . . . . . . . . . . . . . . . . . . . . Alexis H. Jackman and David W. Kennedy Introduction . . . . 109 Deﬁnitions of Rhinosinusitis . . . . 113 Acute Rhinosinusitis . . . . 113 Chronic Rhinosinusitis . . . . 116 Etiologies of Chronic Rhinosinusitis . . . . 117

109

Contents

ix

Summary . . . . 128 References . . . . 129 SECTION III. MICROBIOLOGY 7. Infective Basis of Acute and Recurrent Acute Sinusitis . . . Ellen R. Wald Introduction . . . . 135 Obtaining Specimens . . . . 135 Microbiology of Acute Sinusitis in Children . . . . 137 Microbiology of Acute Community-Acquired Sinusitis in Adults . . . . 138 Conclusion . . . . 141 References . . . . 142

135

8. Infectious Causes of Sinusitis . . . . . . . . . . . . . . . . . . . . Itzhak Brook Introduction . . . . 145 The Oral Cavity Normal Flora . . . . 145 Interfering Flora . . . . 151 Nasal Flora . . . . 152 Normal Sinus Flora . . . . 153 Microbiology of Sinusitis . . . . 154 The Role of Fungi in Sinusitis . . . . 167 Conclusion . . . . 169 References . . . . 169

145

SECTION IV. THERAPEUTIC OPTIONS 9. Antimicrobial Management of Sinusitis . . . . . . . . . . . . . Itzhak Brook Introduction . . . . 179 Antimicrobial Resistance . . . . 179 Beta-Lactamase Production . . . . 180 Antimicrobial Agents . . . . 186 Principles of Therapy . . . . 193 Conclusions . . . . 198 References . . . . 198

179

x

Contents

10. Medical Management of Acute Sinusitis . . . . . . . . . . . . . Dennis A. Conrad Introduction . . . . 203 Rationale for the Recommended Management of Acute Bacterial Sinusitis . . . . 204 Current Recommendations for the Management of Acute Bacterial Sinusitis . . . . 211 References . . . . 216

203

11. Medical Management of Chronic Rhinosinusitis . . . . . . . Alexander G. Chiu and Daniel G. Becker Deﬁnition of CRS . . . . 220 Inciting Factors in Sinusitis . . . . 220 Antimicrobial Therapy . . . . 220 Antimicrobial Agents . . . . 221 Anti-inﬂammatory Agents . . . . 222 Adjunctive Therapy . . . . 223 Maximal Medical Therapy for CRS . . . . 224 Infections Following Functional Endoscopic Sinus Surgery . . . . 225 Nebulized Medications . . . . 226 Topical Antibiotic Irrigations . . . . 227 Intravenous Antibiotics . . . . 227 Aspirin Desensitization . . . . 229 Conclusion . . . . 229 References . . . . 229

219

12. Surgical Management . . . . . . . . . . . . . . . . . . . . . . . . . 233 David Lewis and Nicolas Y. Busaba Introduction . . . . 233 Diagnostic Work-Up . . . . 234 Indications for Paranasal Sinus Surgery . . . . 236 Contraindications for Paranasal Sinus Surgery . . . . 238 Endoscopic (Endonasal) Sinus Surgery . . . . 238 Complications of Endoscopic Sinus Surgery . . . . 245 Image Guidance Systems . . . . 247 Microdebriders and Sinus Surgery . . . . 248 Types of Paranasal Sinus Surgery . . . . 249 Antibiotic Coverage in Paranasal Sinus Surgery: Prophylactic and Post Surgery . . . . 264

Contents

xi

Lasers and Sinus Surgery . . . . 265 Conclusion . . . . 265 References . . . . 266 13. Complications of Acute and Chronic Sinusitis and Their Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gary Schwartz and Steve White Introduction . . . . 269 Pathophysiology . . . . 270 Local Complications . . . . 270 Orbital Infections . . . . 272 Intracranial Complications of Sinusitis . . . . 278 References . . . . 288

269

SECTION V. SINUSITIS AND SPECIFIC DISEASES 14. Sinusitis and Asthma . . . . . . . . . . . . . . . . . . . . . . . . . . 291 Frank S. Virant Introduction . . . . 291 Historical Association of Sinusitis and Asthma . . . . 291 Chemical, Cytokine, and Cellular Mediators of Airway Disease . . . . 292 Impact of Medical Sinus Therapy on Asthma . . . . 294 Impact of Surgical Sinus Therapy on Asthma . . . . 294 Sinusitis as a Trigger for Asthma—Mechanisms . . . . 295 Clinical Implications . . . . 297 Conclusions . . . . 300 References . . . . 300 15. Rhinosinusitis and Allergy . . . . . . . . . . . . . . . . . . . . . . Desiderio Passa`li, Valerio Damiani, Giulio Cesare Passa`li, Francesco Maria Passa`li, and Luisa Bellussi Epidemiology . . . . 305 Pathophysiology . . . . 306 Diagnosis . . . . 308 Treatment . . . . 310 Prevention . . . . 313 References . . . . 314

305

xii

Contents

16. Nosocomial Sinusitis . . . . . . . . . . . . . . . . . . . . . . . . . . 319 Viveka Westergren and Urban Forsum Introduction . . . . 319 Etiology and Pathogenesis . . . . 320 Epidemiology . . . . 328 Diagnosis of an Infectious Sinusitis in the ICU . . . . 339 Microbiology and Choice of Antimicrobials . . . . 342 Treatment . . . . 345 Complications . . . . 346 Prevention . . . . 347 References . . . . 348 17. Cystic Fibrosis and Sinusitis . . . . . . . . . . . . . . . . . . . . . Noreen Roth Henig Introduction . . . . 357 Pathophysiology of CF . . . . 357 Pathophysiology of CF-Related Sinusitis . . . . 358 Microbiology . . . . 359 Clinical Overview of CF Sinusitis . . . . 361 Diagnosis of Cystic Fibrosis . . . . 363 Treatment of CF-Related Sinusitis . . . . 363 Experimental Therapies . . . . 366 Special Considerations . . . . 367 Conclusion . . . . 367 References . . . . 368

357

18. Chronic Rhinosinusitis With and Without Nasal Polyposis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371 Joel M. Bernstein Introduction . . . . 371 Potential Etiologies for the Early Stages of CRS . . . . 373 Microbiology . . . . 374 Epidemiology of CRS with Massive Nasal Polyposis . . . . 375 The Clinical Diagnosis of Nasal Polyposis . . . . 377 Medical and Surgical Therapy of Nasal Polyposis . . . . 380 Pathogenesis of CRS . . . . 381 Conclusions . . . . 397 References . . . . 398

Contents

xiii

19. Sinusitis of Odontogenic Origin . . . . . . . . . . . . . . . . . . Itzhak Brook and John Mumford Introduction . . . . 403 Pathophysiology . . . . 403 Microbiology . . . . 407 Symptoms . . . . 411 Diagnosis . . . . 412 Management . . . . 412 Summary . . . . 415 References . . . . 416

403

20. Fungal Sinusitis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carol A. Kauffman Introduction . . . . 419 Epidemiology . . . . 420 Pathogenesis . . . . 422 Diagnosis . . . . 424 Treatment . . . . 428 Conclusions . . . . 432 References . . . . 433

419

21. Sinusitis in Immunocompromised, Diabetic, and Human Immunodeﬁciency Virus–Infected Patients . . . . . . . . . . . Todd D. Gleeson and Catherine F. Decker Introduction . . . . 437 Sinusitis in Neutropenic Patients . . . . 438 Sinusitis in Diabetic Patients . . . . 444 Sinusitis in HIV-Infected Patients . . . . 446 Conclusion . . . . 449 References . . . . 450 Index . . . . 455

437

Contributors

Naﬁ Aygun The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Medical Institution, Baltimore, Maryland, U.S.A. Daniel G. Becker Department of Otorhinolaryngology—Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A. Luisa Bellussi Ear, Nose, and Throat Department—University of Siena Medical School, Viale Bracci, Siena, Italy Michael S. Benninger Department of Otolaryngology–Head and Neck Surgery, Henry Ford Hospital, Detroit, Michigan, U.S.A. Joel M. Bernstein Departments of Otolaryngology and Pediatrics, School of Medicine and Biomedical Sciences, Department of Communicative Disorders and Sciences, State University of New York at Buffalo, Buffalo, New York, U.S.A. Itzhak Brook Departments of Pediatrics and Medicine, Georgetown University School of Medicine, Washington, D.C., U.S.A. Nicolas Y. Busaba Department of Otolaryngology, Harvard Medical School, VA Boston Healthcare System, Massachusetts Eye and Ear Inﬁrmary, Boston, Massachusetts, U.S.A. Alexander G. Chiu Division of Rhinology, Department of Otorhinolaryngology—Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.

xv

xvi

Contributors

Peter A. R. Clement Department of Otorhinolaryngology and ENT Department, University Hospital, Free University Brussels (VUB), Brussels, Belgium Dennis A. Conrad Division of Infectious Diseases, Department of Pediatrics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, U.S.A. Valerio Damiani Ear, Nose, and Throat Department—University of Siena Medical School, Viale Bracci, Siena, Italy Catherine F. Decker Division of Infectious Diseases, Department of Internal Medicine, National Naval Medical Center, Bethesda, Maryland, U.S.A. Thomas M. File, Jr. Northeastern Ohio Universities College of Medicine, Rootstown, and Infectious Disease Service, Summa Health Service, Akron, Ohio, U.S.A. Urban Forsum Division of Clinical Microbiology, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linko¨ping University, Linko¨ping, Sweden Todd D. Gleeson Division of Infectious Diseases, Department of Internal Medicine, National Naval Medical Center, Bethesda, Maryland, U.S.A. Joshua Gottschall Department of Otolaryngology–Head and Neck Surgery, Henry Ford Hospital, Detroit, Michigan, U.S.A. Noreen Roth Henig Adult Cystic Fibrosis Center, Advanced Lung Disease Center, California Paciﬁc Medical Center, San Francisco, California, U.S.A. Alexis H. Jackman Department of Otorhinolaryngology Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A. Carol A. Kauffman Division of Infectious Diseases, University of Michigan Medical School, Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan, U.S.A. David W. Kennedy Department of Otorhinolaryngology Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.

Contributors

xvii

John H. Krouse Department of Otolaryngology Head and Neck Surgery, Wayne State University, Detroit, Michigan, U.S.A. David Lewis Department of Otolaryngology, Harvard Medical School, Massachusetts Eye and Ear Inﬁrmary, Boston, Massachusetts, U.S.A. John Mumford Department of Periodontics, Naval Postgraduate Dental School, Bethesda, Maryland, U.S.A. Desiderio Passa`li Ear, Nose, and Throat Department—University of Siena Medical School, Viale Bracci, Siena, Italy Francesco Maria Passa`li Ear, Nose, and Throat Department—University of Siena Medical School, Viale Bracci, Siena, Italy Giulio Cesare Passa`li Ear, Nose, and Throat Department—University of Siena Medical School, Viale Bracci, Siena, Italy Gary Schwartz Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A. Robert J. Stachler Department of Otolaryngology Head and Neck Surgery, Wayne State University, Detroit, Michigan, U.S.A. Ovsev Uzunes The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Medical Institution, Baltimore, Maryland, U.S.A. Frank S. Virant

University of Washington, Seattle, Washington, U.S.A.

Ellen R. Wald Department of Pediatrics and Otolaryngology, University of Pittsburgh School of Medicine, Allergy, Immunology, and Infectious Diseases, Pittsburgh, Pennsylvania, U.S.A. Viveka Westergren Division of Clinical Microbiology, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linko¨ping University, Linko¨ping, Sweden Steve White Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A. S. James Zinreich The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Medical Institution, Baltimore, Maryland, U.S.A.

SECTION I. EPIDEMIOLOGY, PRESENTATION AND DIAGNOSIS

1 Sinusitis: Epidemiology Thomas M. File Jr. Northeastern Ohio Universities College of Medicine, Rootstown, and Infectious Disease Service, Summa Health Service, Akron, Ohio, U.S.A.

INTRODUCTION Respiratory tract infections are the most common type of infections managed by health care providers, and they are of great consequence (1,2). In a recent report from the Centers for Disease Control, respiratory tract infections (upper respiratory tract infections, otitis, and lower respiratory tract infections) accounted for 16% of all outpatient visits of patients to physicians (3). Of all the respiratory infections, sinusitis is one of the most common illnesses that affect a high proportion of the population. According to the National Ambulatory Medical Care Survey data, sinusitis is the ﬁfth most common diagnosis for which an antibiotic is prescribed (4). Sinusitis accounted for 9% and 21% of all pediatric and adult antibiotic prescriptions, respectively, written in 2002 (5). Since many cases of sinusitis are viral in etiology, these data actually suggest that antibiotics are frequently misused for the management of this illness. Such inappropriate use leads to increased resistance among respiratory tract pathogens. The inappropriate use of antibiotics is related in part to the fact that sinusitis has been a relatively poorly deﬁned clinical syndrome which is often a self-limited illness associated with wide variations in presenting symptoms, and an incomplete understanding of the pathogenesis and clinical course of the disease. However, recent classiﬁcation of the sinusitis syndrome as well as the

1

2

File

publication of evidence-based guidelines has provided a clear approach to its management (6–8). The appropriate classiﬁcation of sinusitis as well as an awareness of its epidemiology can facilitate better management of this infection. This chapter reviews information concerning the epidemiology of acute sinusitis.

PREVALENCE AND BURDEN OF DISEASE The true prevalence of rhinosinusitis is unclear since various types of sinusitis are often lumped into this single designation. The true prevalence rate likely varies considerably from the diagnostic rate because not all individuals seek care for rhinosinusitis, and because of the inconsistencies in deﬁnitions. Nonetheless, available statistics conﬁrm a high overall prevalence and disease burden. Estimates of the prevalence of acute rhinosinusitis can be extrapolated based on its association with the common cold. A reasonable estimate is that each adult has two to three colds per year, and each child has three to eight colds per year (9). Up to 80% of these upper respiratory illnesses may be associated with rhinosinusitis, equating to over one billion cases of rhinosinusitis annually in the United States (10). It has been suggested that bacterial maxillary sinusitis complicates 0.5% to 2% of all upper respiratory tract infections, which translates into approximately 20 million cases of bacterial acute rhinosinusitis annually (11). This estimate may understate the incidence of rhinosinusitis because the focus was on maxillary sinusitis. According to the 2001 National Health Interview Survey, 17.4% of the American adult population interviewed had been told by a doctor or health care professional that they had sinusitis in the past 12 months (Table 1) (12). The prevalence of chronic rhinosinusitis may be better deﬁned (13). According to the National Ambulatory Medical Care Survey, chronic sinusitis accounts for 12.3 million ofﬁce visits to physicians, or 1.3% of total ofﬁce visits annually (14). Among Canadian adults, the reported prevalence of chronic rhinosinusitis is 5% (15). Unfortunately, the term chronic sinusitis is used to characterize a wide and possibly disparate group of inﬂammatory disorders, and this makes any speciﬁc approach to therapy problematic. The economic impact of rhinosinusitis is considerable. In 1996, the direct cost due to sinusitis was $5.8 billion (16). A primary diagnosis of chronic rhinosinusitis accounted for more than 50% of all expenses. To these costs, indirect costs need to be considered as well, such as days for work lost. Birnbaum et al. recently evaluated the economic burden of respiratory infection, including sinusitis, in an employed population to ascertain the impact of these infections from the perspective of the employer (17). The investigators evaluated more than 63,000 patients with at least one diagnosis for a respiratory infection in 1997 who were identiﬁed in the claims database

(0.08) (0.13) (0.71)a (0.22)a (2.81)a (0.14)

1.6 0.7 1.1 0.4 3.9 0.6 2.4 (0.27) 2.9 (0.31) 1.0 (0.08)

11.8 10.4 9.4 8.0

(0.03) (0.14) (0.40) (0.51)

0.2 1.8 4.7 5.6 (0.23) (0.56) (2.62) (0.98) (6.46)a (0.46)

15.2 (0.71) 11.9 (0.55) 10.7 (0.28)

10.9 11.1 12.2 6.7 16.9 8.5

9.4 (0.29) 12.3 (0.29)

1.7 (0.12) 1.2 (0.09) (0.29) (0.35) (0.55) (0.62)

10.9 (0.21)

1.5 (0.07)

Total Sex Male Female Age 18–44 years 45–64 years 65–74 years 75 years and over Race White Black or African-American American Indian or Alaska Native Asian Native Hawaiian or other Paciﬁc Islander Hispanic or Latino Poverty status Poor Near poor Not poor Region

Asthma

Emphysema

Selected characteristic

(0.22) (0.54) (2.57) (1.11) (2.74)a (0.48)

(0.27) (0.38) (0.54) (0.54)

8.6 (0.55) 8.7 (0.46) 11.3 (0.29)

10.1 8.8 13.3 9.9 3.7 8.4

10.0 11.6 7.5 6.8

8.9 (0.27) 11.1 (0.28)

10.0 (0.20)

Hay fever

(0.30) (0.72) (2.72) (1.20) (4.94)a (0.52)

(0.35) (0.48) (0.77) (0.72)

16.0 (0.71) 16.5 (0.61) 18.8 (0.37)

17.8 17.5 15.5 10.7 11.1 11.1

15.9 21.3 17.2 12.8

12.8 (0.33) 21.7 (0.38)

17.4 (0.27)

Sinusitis

Selected respiratory diseasesa: Chronic

(0.40) (0.17) (1.87)a (0.57) (2.32)a (0.29)

(0.19) (0.28) (0.48) (0.63)

(Continued)

7.9 (0.53) 7.1 (0.43) 5.1 (0.20)

5.7 5.3 5.4 2.3 2.3 3.1

4.5 6.5 6.7 6.9

3.8 (0.19) 7.1 (0.23)

5.5 (0.15)

Bronchitis

Table 1 Percents (With Standard Errors) of Selected Respiratory Diseases Among Persons 18 Years of Age and Over, by Selected Characteristics: United States, 2001

Sinusitis 3

1.3 1.7 1.6 1.1

(0.16) (0.16) (0.13) (0.12)

Emphysema 11.7 10.8 10.6 10.6

(0.52) (0.38) (0.35) (0.44)

Asthma 10.8 8.5 9.5 12.2

(0.49) (0.37) (0.34) (0.45)

Hay fever 16.6 16.2 20.7 13.7

(0.57) (0.51) (0.49) (0.50)

Sinusitis

4.8 5.2 6.4 4.8

(0.30) (0.31) (0.27) (0.29)

Bronchitis

a Respondents were asked in two separate questions if they had ever been told by a doctor or other health professional that they had emphysema or asthma. Respondents were asked in three separate questions if they had been told by a doctor or other health professional in the past 12 months that they had hay fever, sinusitis, or bronchitis. A person may be represented in more than one column. Source: From Ref. 12.

Northeast Midwest South West

Selected characteristic

Selected respiratory diseasesa: Chronic

Percents (With Standard Errors) of Selected Respiratory Diseases Among Persons 18 Years of Age and Over, by Selected Characteristics: United States, 2001 (Continued )

Table 1

4 File

Sinusitis

5

of a national Fortune 100 company. Outcome measures were compared to those of a 10% random sample of beneﬁciaries in the overall employed population. The authors calculated a total cost of care that included not only direct health-care costs, but also disability costs and absenteeism costs. Acute and chronic sinusitis represented the ﬁfth and sixth most common respiratory tract infection with a total number of 9856 and 7368 patients, respectively. This compared to 10,852 treated for acute bronchitis, 5296 treated for chronic bronchitis, 4464 treated for pharyngitis, and 4036 treated for pneumonia. The total aggregate employer cost for treating acute sinusitis and chronic sinusitis was $35,126,784 and $32,824,440, respectively (compared to $46,591,584 and $6,692,439 for pneumonia and pharyngitis) (Table 2) (17). In addition, sinusitis can adversely affect other aspects of quality of life. Matsui et al. observed an decline of cognitive function in elderly people using the Mini-Mental State Examination (18). Chronic sinusitis may affect cognitive function either by decreasing the power of concentration or affecting speciﬁc cognitive functions, which can signiﬁcantly have an impact on quality of life considerations. Therefore, early medical intervention for chronic sinusitis should take into account this potentially neglected effect on cognitive function in the elderly.

EPIDEMIOLOGY AND RISK FACTORS Individuals with allergies or asthma and those who smoke may be predisposed to rhinosinusitis (15,19). For unclear reasons, rhinosinusitis affects more females than males (12,15,20). Women patients between the ages of 25 and 64 years were seen most often (12). When results were considered by single race without regard to ethnicity, Asian adults were less likely to have been told in the preceding 12 months that they had sinusitis compared with white, black, and American Indian or native-Alaska adults (12). Adults in families that were not poor were more likely to have been told that they had sinusitis than adults in poor families. The percentage of adults with sinusitis was higher in the southern area of the United States than any other region (12). Sokol recently reported results from a large study of sinusitis evaluated in the primary care setting, the Respiratory Surveillance Program (20). This study was undertaken over a 10-month period during the 1999–2000 respiratory infection season. Patients were evaluated from 674 community-based practices for data including patient demographics and associated risk factors (Table 3). The diagnosis of rhinosinusitis was based solely on the clinical judgment of the physician investigator. Over 16,000 patients were evaluated and similar to data presented above, females predominated (almost a two to one ratio of female to male). Underlying conditions identiﬁed in this study included smoking, diabetes, and the presence of chronic lung disease (20).

Symptoms of the respiratory system (n ¼ 24,851) Acute upper respiratory infections of multiple or unspeciﬁed sites (n ¼ 13,874) Acute tonsillitis and acute pharyngitis (n ¼ 13,706) Acute bronchitis (n ¼ 10,852) Acute sinusitis (n ¼ 9856) Chronic sinusitis (n ¼ 7368) Chronic bronchitis (n ¼ 5296)

1822

688

628

951 889 1200 1168

3098

613

448

1114 700 990 2054

Inpatient Outpatient

820

674 787

682

350

455

883

Prescription drug

518

449 516

441

315

356

602

Ofﬁce

168

88 102

114

72

81

157

Othera

668

335 404

474

156

297

776

Disability costs

478

429 456

443

211

301

507

Absenteeism costs

5874

3564 4455

4219

2180

2791

7845

Total costs

Table 2 Employer Payments in 1997 per Beneﬁciary by Type of Respiratory Infection, and Employer Overall Costs

31,108,704

35,126,784 32,824,440

45,784,588

29,879,080

38,722,334

194,956,095

Overall costs

6 File

886

1902 787

1038 1047

498

6316 940

1315 1459

680 598

973 455

409

437 413

604 449

371

112 97

242 95

75

621 437

1016 252

179

525 346

491 301

224

4728 4397

11,544 3279

2642

7,158,192 280,924,330

46,591,584 6,692,439

11,793,888

Aggregate employer costs is calculated by multiplying total costs by the number of beneﬁciaries with a speciﬁc condition. a Includes care at patient’s home, nursing/extended care facility, psychiatric day-care facility, substance abuse treatment facility, and independent clinical laboratories. Source: From Ref. 17.

Strep throat and scarlet fever, chronic pharyngitis and nasopharyngitis, chronic diseases of the tonsils and adenoids (n ¼ 4464) Pneumonia (n ¼ 4036) Acute nasopharyngitis (acute cold) and acute laryngitis (n ¼ 2041) Inﬂuenza (n ¼ 1514) Unique individuals in respiratory infections sample (n ¼ 63,890)

Sinusitis 7

8

File

Table 3 Demographic Data for Sinusitis (From the Respiratory Surveillance Program) Demographic Age (yr), mean (range) Sex (460 none speciﬁed) % female/% male Ethnicity (% total) White African American Hispanic Asian Other Unknown Smoker (%) Diabetes (%) COPD (%)

Overall (n ¼ 16,135) 44 (1–97) 62/35 13,603 (86%) 1018 (6.3%) 557 (3.5%) 227 (1.4%) 76 (0.5%) 654 (4.1%) 3813 (24%) 674 (4.2%) 688 (4.3%)

460 no sex speciﬁed. Abbreviation: COPD, chronic obstructive pulmonary disease. Source: From Ref. 20.

Predisposing Conditions of Rhinosinusitis In addition to smoking, there are many other conditions associated with rhinosinusitis. These include allergic rhinitis, asthma, nasal polyps, aspirin hypersensitivity, cystic ﬁbrosis, and immune deﬁciency [particularly immunodeﬁciency virus (HIV) infection] (Tables 4 and 5). The occurrence of secondary bacterial sinusitis is highly associated with prior viral respiratory illnesses (10,11). An important area of disease leading to secondary bacterial sinusitis is obstruction at the ostiomeatal complex. A variety of factors may lead to obstruction of the ostium. The most common predisposing factor is viral infection, which causes edema and inﬂammation of the nasal mucosa. In addition to viral rhinosinusitisrelated cases, acute bacterial sinusitis occurs related to allergy and nasal obstruction due to polyps, foreign bodies, and tumors. Less common risk factors associated with a predisposition for bacterial sinusitis are immune deﬁciencies such as agammaglobulinemia and human HIV infection; abnormalities of polymorphonuclear cell function; structural defects, such as cleft palate; and disorders of mucociliary clearance, including cilial dysfunction and cystic ﬁbrosis (21). Rhinosinusitis and the Common Cold The relationship between rhinosinusitis and the common cold has been well established. In a sentinel prospective study of 110 adults, Gwaltney et al. evaluated the ﬁndings on CT examination of patients with rhinosinusitis (10).

Sinusitis

9

Table 4 Extrinsic and Intrinsic Potential Causes of Chronic Rhinosinusitis Extrinsic causes of CRS can broadly be broken down into: 1. Infectious (viral, bacterial, fungal, parasitic) 2. Noninfectious/inﬂammation a. Allergic–IgE-mediated b. Non–IgE-mediated hypersensitivities c. Pharmacologic d. Irritants 3. Disruption of normal ventilation or mucociliary drainage a. Surgery b. Infection c. Trauma Intrinsic causes contributing to CRS: 1. Genetic a. Mucociliary abnormality i. Cystic ﬁbrosis ii. Primary ciliary dysmotility b. Structural c. Immunodeﬁciency 2. Acquired a. Aspirin-hypersensitivity associated with asthma and nasal polyps b. Autonomic dysregulation c. Hormonal i. Rhinitis of pregnancy ii. Hypothyroidism d. Structural i. Neoplasms ii. Osteoneogenesis and outﬂow obstruction iii. Retention cysts and antral choanal polyps e. Autoimmune or idiopathic i. Granulomatous disorders 1. Sarcoid 2. Wegener’s granulomatosis ii. Vasculitis 1. Systemic lupus erythematosus 2. Churg-Straus syndrome iii. Pemphigoid f. Immunodeﬁciency Source: From Ref. 13.

Among 31 patients who had CT scans performed within 24 to 48 hours of assessment, 24 (77%) had occlusion of the ethmoid sinus, 27 (87%), had abnormalities of one or both maxillary sinuses, 20 (65%) had abnormalities of the ethmoid sinuses, 10 (32%) had abnormalities of the frontal sinuses, and 12 (39%) had abnormalities of the sphenoid sinuses. Rhinovirus was

10

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Table 5 Factors Associated with Chronic Rhinosinusitis Systemic host factors

Local host

Environmental

Allergic Immunodeﬁciency

Anatomic Neoplastic viral, bacterial, fungal Acquired-mucociliary dysfunction Medications Trauma Surgery

Microorganisms

Genetic/congenital Mucociliary dysfunction Endocrine Neuromechanism

Noxious chemicals, pollutant, smoke

Source: From Ref. 13.

detected in the secretions of 7 of 17 (41%) of these patients. The patients received no medical treatment for their infections; 14 patients with sinus abnormality as seen on the initial CT scan had repeat scans, and one of these reported resolution of symptoms. Of signiﬁcance, 11 of these 14 (79%) showed clearing or marked improvement in sinus abnormalities. It is evident from this study that the common cold is associated with frequent involvement of the paranasal sinuses. Rhinosinusitis and Allergy Several studies suggest an association between rhinosinusitis and allergic sinusitis (22,23). Allergic rhinitis predisposes the patient to sinusitis since it can be associated with inﬂammation and obstruction of the ostia. Thus, allergic rhinitis and acute bacterial sinusitis can overlap. Rhinosinusitis and Asthma Sinusitis is often seen in patients with asthma and often exacerbates the severity of the episode (24). Although the pathophysiology of the association between asthma and sinusitis is not very clear, it may be related to damage induced by the eosinophil, a prominent component of the inﬂammatory process that is characteristic of both diseases. A reﬂex phenomenon linking inﬂammation in the sinuses to subsequent inﬂammation in the lower airways has been proposed. PATHOGENS OF BACTERIAL SINUSITIS Epidemiology of Streptococcus pneumoniae and Haemophilus influenzae When sinus puncture aspirates are used to obtain secretions for culture from patients with acute sinusitis, results consistently show that Streptococcus pneumoniae and Haemophilus inﬂuenzae are the most important bacterial

Sinusitis

11

pathogens. Other organisms occasionally found include Moraxella catarrhalis, other streptococcal species (e.g., Streptococcus pyogenes), Staphylococcus aureus, and anaerobes (e.g., Prevotella spp., Peptostreptococcus spp., Fusobacterium spp.). Of all the above pathogens, S. pneumoniae is considered the most signiﬁcant from the standpoint of virulence and clinical impact. S. pneumoniae can be transmitted directly or through fomites; transmission is facilitated by crowding, such as in daycare centers or extended care facilities. Children are often heavily colonized with S. pneumoniae, and adults not exposed to children generally have a lower prevalence of S. pneumoniae infection. Risk factors for S. pneumoniae infection in adults include active or passive smoke exposure and presence of chronic diseases. S. pneumoniae infections occur most commonly during the winter months, in part due to the secondary relationship to viral infections. H. inﬂuenzae is indigenous to humans and readily colonize the nasopharynx. Spread from one individual to another occurs by airborne droplets or by direct contact with secretions. The majority of sinus infections are due to nonencapsulated strains. SINUSITIS AND HIV In the pre-highly active anti-retroviral therapy (HAART) era, up to 70% of patients with HIV experienced at least one bout of acute sinusitis during the course of their disease, and 58% experienced recurrent infections (25). As patients are now living longer with the availability of HAART, the prevalence of acute and chronic sinusitis in HIV-infected patents has increased. In a study of 7513 HIV-infected patients enrolled from November 1990 to November 1999, the incidence of one or more diagnoses of sinusitis was 14.5% (26). The mean CD4 count at the time of sinusitis was 391. Although the authors felt the incidence of sinusitis in individuals infected with HIV is frequent, there was no association between sinusitics and an increased hazard of death after adjusting results for the level of immunodeﬁciency age, gender, and race. The organisms associated with acute sinusitis in HIV patients are similar to the pathogens in other patients, with S. pneumoniae and H. inﬂuenzae being predominant. However, there is a higher occurrence of S. aureus and Pseudomonas aeruginosa in the HIV-infected patient than in the noninfected patient (Table 6) (27). The common occurrence of P. aeruginosa in HIV-infected patients probably reﬂects an impaired mucociliary transport often associated with HIV infection. In addition, more unusual organisms are also commonly found, particularly if immunodeﬁciency progresses. As the CD4 counts of patients dip below 200, these patients become susceptible to more opportunistic infections. Opportunistic and atypical infections include cytomegalovirus, Aspergillus spp., and Mycobacterium spp. (27).

12

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Table 6 Sinus Pathogens in HIV Streptococcus pneumoniae Streptococcus viridans Pseudomonas aeruginosa Haemophilus inﬂuenzae Coagulase-negative Staphylococci Staphylococcus aureus Candida albicans Klebsiella pneumoniae Listeria monocytogenes Torulopsis glabrata

19% 19% 17% 13% 13% 9% 4% 2% 2% 2%

In antral washings from 41 HIV patients with acute sinusitis, four had multiple pathogens. Source: From Ref. 27.

NOSOCOMIAL SINUSITIS Sinusitis is a relatively common infection in patients treated in an intensive care unit (ICU). An epidemiologic study in an ICU orally-intubated population found the incidence of sinusitis, as diagnosed by cultures of maxillary sinus secretion, was 10% (28). In another study of 300 patients, the incidence of infectious sinusitis was estimated at 20% after eight days of mechanical ventilation in patients that were orotracheally or nasotracheally intubated (29). However, in a study designed to search for nosocomial sinusitis in patients who were intubated in an ICU, Holzapfel et al. found 80 patients among 199 study patients to have infectious nosocomial maxillary sinusitis (30). In this study, all patients who were nasotracheally intubated were evaluated by a sinus CT scan if body temperature was 38 C. When CT scan showed an air-ﬂuid level and/or an opaciﬁcation within a maxillary sinus, a transnasal puncture was performed. Critieria for nosocomial sinusitis were sinus CT scan ﬁndings consistent with sinusitis, mechanical ventilation, macroscopic purulent sinus aspiration, and quantitative culture of the aspirated material with 103 cfu/mL. Among the 80 patients, infection was due to polymicrobial ﬂora in 44 patients and 138 organisms were isolated. The most common organisms were Eshcerichia coli (12), P. aeruginosa (12), Proteus spp. (10), Hemophilus spp. (7), Klebsiella spp. (6), Enterobacter spp. (6), S. aureus (10), Streptococcus spp. (30), anaerobes (15), and Candida albicans (10). Multiple factors can promote nosocomial sinusitis in critically ill patients. Placement of endotracheal or gastric tubes through the nose can irritate the nasopharyngeal mucosa, causing edema in the region of the ostial meatal complex. Nasal tubes can also directly obstruct sinus drainage by acting as foreign bodies. Placing tubes via the mouth does not entirely eliminate the risk of nosocomial sinusitis, but studies suggest the risk is

Sinusitis

13

lessened. In one study, the incidence of sinusitis was higher in patients intubated nasotracheally as compared to those by the oropharyngeal route (31). Additional factors which may play a role in ICU patients include the supine position and limitation of head movements (which may prevent natural sinus drainage normally caused by gravity), positive-pressure ventilation, impaired ability to cough or sneeze, and the absence of airﬂow through the nares in ventilated patients.

REFERENCES 1. File TM Jr. The epidemiology of respiratory tract infections. Semin Respir Infect 2000; 15(3):184–194. 2. File TM Jr, Hadley JA. Rational use of antibiotics to treat respiratory tract infections. Am J Manag Care 2002; 8:713–727. 3. Armstrong GL, Pinner RW. Outpatient visits for infectious diseases in the United States, 1980 through 1996. Arch Intern Med 1999; 159:2531–2536. 4. McCaig LF, Hughs JM. Trends in antimicrobial drug prescribing among ofﬁcebased physicians in the United States. JAMA 1995; 273:214–219. 5. Scott Levin Prescription Audit from Verispan, L.L.C., January–December, 2002. 6. Lanza DC, Kennedy DW. Adult rhinusitis deﬁned. Otolaryngol Head Neck Surg 1997; 117(3 Pt 2):S1–S7. 7. Anon JB, Jacobs MR, Poole MD, Ambrose PG, Benninger MS, Hadley JA, Craig WA, and The Sinus and Allergy Health Partnership. Antimicrobial treatment guidelines for acute bacterial rhinosinusitis 2004. Otolaryngol Head Neck Surg 2004; 130(suppl 1):1–45. 8. Brook I, Gooch WM III, Jenkins SG, Pichichero ME, et al. Medical management of acute bacterial sinusitis. Recommendations of a Clinical Advisory Committee on Pediatric and Adult Sinusitis. St Louis: Annals Publishing, 2000. 9. Dingle JH, Badger GF, Jordan WS Jr. Illness in the home: a study of 25,000 illnesses in a group of Cleveland families. Cleveland: The Press of Western Reserve University, 1964. 10. Gwaltney JM Jr, Phillips CD, Miller RD, et al. Computed tomographic study of the common cold. N Engl J Med 1994; 330:25–30. 11. Gwaltney JM Jr, Wiesinger BA, Patrie JT. Acute community-acquired bacterial sinusitis: the value of antimicrobial treatment and the natural history. Clin Infect Dis 2004; 38:227–233. 12. Lucas JW, Schiller JS, Benson V. Summary health statistics for U.S. adults: National Health Interview Survey, 2001. National Center for Health Statistics. Vital Health Stat 2001; 10:218. 13. Benninger MS, et al. Adult chronic rhinosinusitis: deﬁnitions, diagnosis, epidemiology, and pathophysiology. Otolaryngol Head Neck Surg 2003; 129S(suppl 3): S1–S32. 14. Cherry DK, Burt CW, Woodwell DA. National Ambulatory Medical Care Survey: 2001 Summary. Advance Data form Vital and Health Statistics; no. 337. Hyattsville, MD: National Center for Health Statistics, 2003.

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15. Chen Y, Dales R, Lin M. The epidemiology of chronic rhinosinusitis in Canadians. Laryngoscope 2003; 113:1199–1205. 16. Durr DG, Desrosiers MY, Dassa C. Impact of rhinosinusitis in health care delivery: the Quebec experience. J Otolaryngol 2001; 30:93. 17. Birnbaum HG, Morley M, Greenberg MS, Colice GL. Economic burden of respiratory infections in an employed population. Chest 2002; 122:603–611. 18. Matusi T, Arai H, Nakajo M, Mauyama M, Ebihara S, et al. Role of chronic sinusitis in cognitive functioning in the elderly. J Am Geriatr Soc 2003; 51: 1818–1819. 19. Lieu JE, Feinstein AR. Conﬁrmations and surprises in the association of tobacco use with sinusitis. Arch Otolarynygol Head Neck Surg 2000; 126: 940–946. 20. Sokol W. Epidemiology of sinusitis in the primary care setting: results from the 1999–2000 respiratory surveillance program. Am J Med 2001; 111(9A): 19S–24S. 21. Casiano RR. Sinusitis: a complex and challenging disease. Mediguide Infect Dis 2001; 21(1):1–5. 22. Alho OP, Karttunen TJ, Karttunen R, Tuokko H, Koskela M, Suramo I, Ukhari M. Subjects with allergic rhinitis show signs of more severely impaired paranasal sinuus function during viral colds than non allergic subjects. Allergy 2003; 58:767–771. 23. Mucha SM, Baroody FM. Relationships between atopy and bacterial infections. Curr Allergy Asthma Rep 2003; 3:232–237. 24. Osur SL. Viral respiratory infections in association with asthma and sinusitis: a review. Ann Allergy Asthma Immunol 2002; 89:553–560. 25. Godofsky EW, Zinreich J, Armstrong M, et al. Sinusitis in HIV-infected patients: a clinical and radiographic review. Am J Med 1992; 93:163–170. 26. Belafsky PC, Amedee R, Moore B, Kissinger PJ. The association between sinusitis and survival among individuals infected with the human immunodeﬁciency virus. Am J Rhinol 2001 Sept–Oct; 15(5):343–345. 27. Milgrim LM, Rubin JS, Rosenstreich DL, et al. Sinusitis in human immunodeﬁciency virus infection: typical and atypical organisms. J Otolaryngol 1994; 23:450–453. 28. George DL, Falk PS, Nunally K. Nosocomial sinusitis in medical intensive care unit patients: a prospective epidemiologic study. Infect Control Hosp Epidemiol 1992; 21:497. 29. Holzapfel L, Chevret S, Madinier G, Onen F, Demingeon G, Coupry A, Chaudet M. Incidence of long term oro- or nastotracheal intubation on Nosocomial maxillary sinusitis and pneumonia: results of a randomized clinical trial. Crit Care Med 1993; 21:1132–1138. 30. Holzapfel L, Chastang C, Deningeon G, Bohe J, Piralla N, Coupry A. Randomized study assessing the systematic search for maxillary sinusitis in Nasotracheally Mechanically Ventilated Patients. Am J Respir Crit Care Med 1999; 159:695–701. 31. Rouby JJ, Laurent P, Gosnach M, et al. Risk factors and clinical relevance of nosocomial maxillary sinusitis in the critically ill. Am J Respir Crit Care Med 1996; 150:776–783.

2 Classification of Rhinosinusitis Peter A. R. Clement Department of Otorhinolaryngology and ENT Department, University Hospital, Free University Brussels (VUB), Brussels, Belgium

INTRODUCTION In 1972, Douek wrote that ‘‘classiﬁcation has an important place in medicine, as it forms the framework upon which diagnosis is made possible, etiology recalled and separated, and treatment decided. It remains, however, an intellectual system imposed onto a nature that has rarely rigid boundaries’’ (1). Now, more than 30 years later, this statement is still valid. This chapter reviews the different classiﬁcations of rhinosinusitis, and attempts to explain why in the course of time these classiﬁcations were changed. By acquiring new information about the natural history of rhinosinusitis based on novel imaging techniques such as MRI, CT scanning, and nasal endoscopy, new insights on the pathophysiology of the disease were gained. Because of better culture techniques; and recent advances in histocytochemistry of inﬂammation; it became obvious that the classiﬁcation of this disease needed to be adapted and redeﬁned step-by-step. Rhinosinusitis Versus Sinusitis There exists a general agreement that rhinosinusitis can be deﬁned as any inﬂammation of the paranasal sinus mucosa (2). Johnson and Ferguson stated that because the lining of the mucosa and the paranasal sinuses is continuous, an inﬂammation of the nasal cavity is usually associated with inﬂammation of the sinus lining (3). The faculty of the staging and therapy 15

16

Clement

group shared the same opinion and stated that the term rhinosinusitis is perhaps more precise than the term sinusitis. The reasons are that sinusitis does not typically develop without prior rhinitis, isolated sinus disease without rhinitis is rare, the mucous membrane lining of the nose and the paranasal sinus is continuous, and two of the prominent features of sinusitis— nasal obstruction and drainage—are associated with rhinitis symptoms (4). The Task Force on Rhinosinusitis (TFR) preferred the term rhinosinusitis as well (5). On occurrences in children, the members of the Consensus Panel on Pediatric Rhinosinusitis preferred to speak of rhinosinusitis since rhinitis and sinusitis are often a continuum of the disease (6). Radiological Changes as Signs of Sinusitis Havas et al. (7) found abnormal appearances of the paranasal sinuses on CT scan in 42.5% of asymptomatic adults and Bolger et al. (8) found a similar proportion of 41.7% in patients scanned for nonsinus reasons. As a possible explanation, Bolger et al (8). suggested that these abnormalities could be induced by normal variations of the sinus mucosa, asymptomatic chronic sinus disease, and mild to moderately symptomatic undiagnosed chronic sinusitis. In a CT scan study of children undergoing nonsinusitis evaluation, Diament et al. (9) detected maxillary and ethmoidal thickening in 50% of the patients. Similar ﬁgures were found by Gordts et al. (10,11) who demonstrated in an MRI study of a non-ENT population of adults (without any complaints and a blank surgical history) that there existed on 40% abnormalities of the mucosa, and in 45% of the cases in a non-ENT population of children. All these imaging studies show us that imaging signs of sinusitis, in particular pathological mucosal swelling, can occur in completely asymptomatic adults and children. The meaning of these ﬁndings is unclear, and therefore, many clinicians claim that one has to treat patients and not CT or MRI scans. The problem, however, remains that subclinical, silent, or asymptomatic sinusitis exists. Whether it needs to be diagnosed or treated in order to prevent manifest sinusitis is another question that has not been investigated yet. The aim of this chapter is to discuss the classiﬁcation of symptomatic rhinosinusitis. Rhinosinusitis can be deﬁned as any inﬂammation of the nasal and paranasal sinus mucosa, resulting in signs and symptoms. Parameters Used for Classification According to Pinheiro et al. (12), classiﬁcation of rhinosinusitis should be done along ﬁve axes: i. Clinical presentation (duration: acute, subacute, and chronic) ii. Anatomical site of involvement (ethmoid, maxillary, frontal, and sphenoid) iii. Responsible microorganism (viral, bacterial, and fungal)

Classification of Rhinosinusitis

17

iv. Presence of extra sinus involvement (complicated and uncomplicated) v. Modifying or aggravating factors (e.g., atopy, immunosuppression, ostiomeatal obstruction, etc.) According to these authors, a complete classiﬁcation of sinusitis according to these ﬁve axes is essential to tailor the treatment for the particular situation. As an example of this axes system, a possibility would be chronic (i), frontal (ii), bacterial (iii) sinusitis complicated by frontal bone osteomyelitis (iv) and aggravated by immunosuppression due to diabetes mellitus (v).

CLASSIFICATIONS OF SINUSITIS Most classiﬁcation systems of rhinosinusitis, however, are based on the duration of symptoms and/or the speciﬁc sinus involved (13). In 1984, Kern stated that a classiﬁcation of sinusitis based on pathology is useful in patient management (14). In addition to naming the involved sinuses, the classiﬁcation should contain some concepts as to the duration of the sinus infection. Kern deﬁned acute suppurative sinusitis, on an arbitrary basis, as any infectious process in a paranasal sinus lasting from one day to three weeks, and subacute sinusitis as a sinus infection that lingers from three weeks to three months, during which period epithelial damage in the sinuses may still be reversible (14). Irreversible changes usually occur after three months of subacute sinusitis, leading into the next phase of chronic sinusitis that is any infection lasting longer than three months and requiring surgery for sinus ventilation and drainage. From this deﬁnition, it is obvious that at that time sinusitis was considered to be a mainly infectious process, and that after three months the mucosal changes were considered to be irreversible. This concept that after three months irreversible mucosal changes had occurred corresponds with the philosophy of the Caldwell–Luc operation that insisted on meticulously removing the mucus lining of the maxillary sinus in toto (15). On the contrary Wigand showed that restoration of ventilation and drainage after removal of cysts and polyps initiates the recovery of diseased mucosa (16,17). At this time, a very new and important concept was introduced to preserve as much mucosa as possible because most of the mucosal disease seemed to be reversible after adequate drainage and ventilation. In the eighties, the basic pathological concept of sinusitis consisted of bacterial infection due to sinus ostium obstruction, followed by hypoxia and a series of events leading to the production of thick retained secretions creating a perfect situation for bacterial multiplication (14), i.e., the sinusitis cycle (18). It was demonstrated, however, from standard x-ray examination of the paranasal sinuses in 144 consecutive adult patients with perennial rhinitis, that 20% showed major changes (total opacity of the maxillary sinus) and

18

Clement

another 20% showed minor changes (19). Based on a CT scan study in atopic patients, Iwens et al. concluded that signs of sinusitis exist in about 60% of the children and adults (20). Young children (three–nine years of age) showed more severe sinusitis (50% to total opacity of the involved sinuses) on the CT scans in 30% to 40% of the cases, while older children and adults more often had signs of mild sinusitis (mucosal swelling of more than 4 mm and an opacity of less than 50%). In 1992 Shapiro et al. concluded that there existed a general agreement that sinusitis can be deﬁned as an inﬂammation (not infection) of the paranasal mucosa (2). The authors proposed the following deﬁnition of sinusitis (Table 1) (2): Acute sinusitis can be deﬁned by certain major and minor criteria that exist for longer than the typical viral upper respiratory tract infection (URTI), more than seven days. The presence of two or more minor criteria for more than seven days is highly likely to signify acute sinus disease, which is usually bacterial. If the signs and symptoms fulﬁll these criteria, the presence of one positive major diagnostic test result is conﬁrmatory, whereas the minor tests may be considered supportive. Another symptom, acute onset of fever with purulent rhinorrhea, is also considered highly likely to indicate acute bacterial sinusitis. Table 1 Clinical Diagnosis of Sinusitis Signs and symptoms Major criteria Purulent nasal discharge opaciﬁcation Purulent pharyngeal drainage/ mucosa Purulent postnasal drip Cough Minor criteria Periorbital oedema Headache Facial pain Tooth pain Earache Sore throat Foul breath Increased wheeze Fever Source: Adapted from Ref. 2.

Diagnostic tests Major criteria Water’s radiograph or ﬂuid level: thickening ﬁlling 50% of antrum Coronal CT scan: thickening of or opaciﬁcation of sinus mucosa

Minor criteria Nasal cytology study (smear) with neutrophils and bacterimiae Ultrasound studies

Probable sinusitis Signs and symptoms: 2 major, 1 minor and 2 minor criteria Diagnostic tests: 1 major ¼ conﬁrmatory, 1 minor ¼ supportive

Classification of Rhinosinusitis

19

Chronic sinusitis was referred as a disease that lasted more than three months that is manifested by the presence of long-term symptoms without an ongoing need for antibiotic therapy. Thus, chronic sinusitis might occur on a non-infectious basis. Subacute sinusitis was used for the gray zone between disease lasting less than a month (acute) and lasting more than three months (chronic).

Since these guidelines were published, it became more appropriate to refer to inﬂammation rather than infection when the term sinusitisis was used. Inﬂammation covers infectious as well as noninfectious mechanisms. Using CT scans, Gwaltney et al. showed that during a common cold of two- to four-day duration, more than 80% of the cases showed abnormalities of the sinuses mucosa (21). These abnormalities of the inﬁndibula and sinuses cleared or markedly improved within two weeks. In a prospective study using MRI, Leopold et al. studied the evolution of acute maxillary sinusitis (manifested by facial pain, fever, and purulent rhinorrhea) in 13 previously healthy subjects (22). The MRI analysis of the volume percentage of air in the involved sinuses showed that only half of the opaciﬁcation had resolved by 10 days and the sinuses were only about 80% aerated by 56 days. This study showed that although antibiotic treatment of acute maxillary sinusitis generally results in clinical resolution of symptoms within one week, mucosal changes, however, could persist for eight weeks or more. All these new insights showed that the classiﬁcation of rhinosinusi tis had to be redeﬁned and these led in 1993 to an international conference on sinus disease, chaired by Kennedy (23) in Princeton, New Jersey. The following deﬁnitions were proposed in the Princeton meeting classiﬁcation. 1. Acute sinusitis is deﬁned as a symptomatic sinus infection in which symptoms persist no longer than six to eight weeks or there are fewer than four episodes per year of acute symptoms of 10 days duration. Sinusitis is acute when episodes of infection resolve with medical therapy leaving no signiﬁcant mucosal damage. 2. Chronic sinusitis is a persistent sinusitis that cannot be alleviated by medical therapy alone, and involves radiographic evidence of mucosal hyperplasia. In adults, it is deﬁned as eight weeks of persistent symptoms or signs, or four or more episodes per year of recurrent acute sinusitis, each lasting at least 10 days, in association with persistent changes on CT scan four weeks after medical therapy without intervening acute infection (URTI).

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3. Recurrent acute sinusitis is deﬁned as repeated acute episodes that resolve with medical therapy, leaving no signiﬁcant mucosal damage. The faculty of the staging and therapy group published the symptoms and signs needed for establishing the diagnosis of chronic sinusitis and divided them in major and minor ones (Table 2) (4). In 1997, the International Rhinosinusitis Advisory Board (IRAB) published the clinical classiﬁcation of rhinosinusitis in adults (24). They deﬁned acute rhinosinusitis as a sinusitis with an acute onset of symptoms and a duration of symptoms less than 12 weeks and symptoms that resolve completely. Recurrent acute rhinosinusitis was deﬁned as being more than one and less than four episodes of acute rhinosinusitis per year, a complete recovery between the attacks, and a symptom-free period of more than or equal to eight weeks between the acute attacks in absence of medical treatment. The diagnosis of acute community-acquired bacterial rhinosinusitis (ACABRS) is judged probable if two major criteria (symptoms), or one major and two or more minor criteria, are present. The authors, however, recognize that none of these criteria are sensitive and speciﬁc for the diagnosis of ACABRS, so that an additional standard was necessary to prove the diagnostic accuracy. Sinus puncture studies had shown that the symptoms that persist longer than 10 days without improvement are suggestive of bacterial rather than viral rhinosinusitis (25). Hence, if a patient with a cold or inﬂuenza illness does not improve or is worse after 10 days, the authors recommended treatment with antibiotics. Some symptoms such as fever, facial erythema, and maxillary toothache have high speciﬁcity but low sensitivity, and when present, the diagnosis of ACABRS is warranted. They recognized that ACABRS needs to be differentiated from acute nosocomial or hospital-acquired bacterial rhinosinusitis (AHABRS). Nosocomial sinusitis is most often polymicrobial and is usually caused by those organisms that are most prevalent in that particular institution (12). AHABRS is often seen in critically ill or immunosuppressed patients. Table 2 Chronic Sinusitis Major Nasal congestion or obstruction Nasal discharge Headache Facial pain or pressure Olfactory disturbance Source: Adapted from Ref. 4.

Minor Fever Halitosis

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Chronic rhinosinusitis was deﬁned as a sinusitis with a duration of symptoms more than 12 weeks, which shows persistent inﬂammatory changes on imaging and lasts for more than or equal to four weeks after starting appropriate medical therapy (with no intervening acute episodes). The authors also deﬁned the acute exacerbation of chronic rhinosinusitis as a worsening of existing symptoms or appearance of new symptoms and a complete resolution of acute (but not chronic) symptoms between episodes. The authors presented their deﬁnitions and classiﬁcation of infectious rhinosinusitis with a summary of current views on etiology and management. They admitted that the deﬁnitions based on the severity and duration of symptoms were imperfect, the duration of the acute episodes chosen in the various deﬁnitions was arbitrary, and the clinical signiﬁcance of abnormal ﬁndings on imaging investigation was debatable. For the duration in the deﬁnition of chronic sinusitis, they followed the FDA recommendation to consider the condition if symptoms persist for more than 12 weeks (24). From a clinical perception, the authors admitted that the deﬁnition of chronic rhinosinusitis (CRS) is often subjective and is based on symptoms that are vague, nonlocalized, and nonspeciﬁc. The relationship between the ﬁndings on endoscopic examination, the radiographic appearance and speciﬁc symptoms, and the severity is poorly deﬁned. The authors also realize that there appears to be an ill-deﬁned group between the acute and the chronic conditions, and they suggest that this problem can be overcome by the use of the term ‘‘subacute’’ which spans the interval, but in other respects deﬁes the deﬁnition, and it does not represent a histopathologic entity. The IRAB also proposed another classiﬁcation based on microbiological etiology, i.e., probable viral rhinosinusitis (nasal congestion, obstruction, nasal discharge, facial pressures/pain without fever, toothache, facial tenderness, erythema, and swelling), acute bacterial rhinosinusitis (same symptoms as viral rhinosinusitis) but with fever-fever is an exclusion criteria for viral rhinosinusitis or persisting without improvement for more than eight days), recurrent acute rhinosinusitis (incidence of more than four episodes a year), chronic sinusitis (with symptoms lasting longer than 12 weeks), and acute exacerbation of chronic rhinosinusitis (acute worsening of chronic sinusitis symptoms) (24). Although the IRAB recognizes the occurrence of sinusitis in allergic patients, it still considers every sinusitis to be of infectious origin. Their deﬁnition requires the inclusion of the parameter of duration in the classiﬁcation based on the microbiological etiology. What was not taken into consideration by IRAB is the report by Gwaltney et al. that in maxillary sinus aspirates of patients with acute community acquired sinusitis (ACAS: the most typical example of bacterial sinusitis), viruses and fungi are found in addition to bacteria (Table 3) (26). The same working deﬁnitions that took into account the duration of the diseases were developed by TFR, sponsored by the American Academy of Otolaryngology/Head and Neck Surgery (AAO-HNS) (5). This report

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Table 3 Clinical Criteria for the Diagnosis of Acute Community-Acquired Bacterial Rhinosinusitis (ACABRS) IRAB Guidelines Major

Minor

Purulent anterior and posterior discharge Nasal congestion Facial pressure or pain Fever

Cough Headache Halitosis Earache

Diagnosis of ACABRS: two major criteria, or one major criterion and two or more minor criteria. Source: Adapted from Ref. 24.

details the major and minor symptoms (Table 4) and deﬁnes sinusitis as the condition manifested by an inﬂammatory response of the nasal cavity and sinuses, and not an infection of these structures. It prefers the term rhinosinusitis to sinusitis as the mucous blanket of the sinuses is in continuity with that of the nasal cavity. They recognized that the multifactorial nature and multiple causes of rhinosinusitis make it difﬁcult to deﬁne its cause in a given patient. They therefore concluded that it is currently impractical to deﬁne rhinosinusitis on the basis of its cause. An important differentiation between acute and chronic was made on the basis of histopathology, where

Table 4 Factors Associated with the Diagnosis of Chronic Sinusitis Major factors Facial pain, pressure (alone does not constitute a suggestive history for rhinosinusitis in absence of another major symptom) Facial congestion, fullness Nasal obstruction/blockage Nasal discharge/purulence/discolored nasal drainage Hyposmia/anosmia Purulence in nasal cavity on examination Fever (acute rhinosinusitis only) in acute sinusitis alone does not constitute a strongly supportive history for acute in the absence of another major nasal symptom or sign Source: Adapted from Ref. 5.

Minor factors Headache Fever (all nonacute) Halitosis Fatigue Dental pain Cough Ear pain/pressure/ fullness

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acute rhinosinusitis is predominantly viewed as an exudative process associated with necrosis, hemorrhage, and/or ulceration, in which neutrophils predominate, whereas CRS is predominantly a proliferative process associated with ﬁbrosis of the lamina propria, in which lymphocytes, plasma cells, and eosinophils predominate along with perhaps changes in bone. Another important statement by the TRF is that a pathological review may also reveal a variety of ﬁndings that include, but are limited to, varying degrees of eosinophils in tissues and secretions, as well as the polyp formation and the presence of granulomas, bacteria, or fungi. This statement is important as it highlights the importance of inﬂammation (eosinophilic inﬁltration) rather than the infection, the presence of fungi, or the formation of nasal polyps in CRS. The TFR also recognizes the concept of subacute rhinosinusitis for several reasons (5): 1. When polled, the physicians serving on the TFR indicated that they would treat rhinosinusitis lasting less than two to three weeks differently than they would treat a rhinosinusitis lasting 6 to 12 weeks. 2. Similar issues concerning otitis media had been heatedly debated until the otitis media literature arbitrarily deﬁned acute otitis media as those lasting three weeks, subacute as lasting 3 to 12 weeks, and chronic otitis media as those lasting more than 12 weeks (27). 3. The FDA had no formal deﬁnition to describe the condition that lasts 4 to 12 weeks (less than four weeks is acute, more than four weeks is chronic). The TFR deﬁnes ﬁve different classiﬁcations of adult rhinosinusitis (5): 1. Acute rhinosinusitis is a sinusitis with a sudden onset and lasting up to four weeks. The symptoms resolve completely, and once the disease has been treated, antibiotics are no longer required. A strong history consistent with acute rhinosinusitis includes two or more major factors (Table 4) or one major and two minor factors. However, the ﬁnding of nasal purulence is a strong indicator of an accurate diagnosis. A suggestive history for which acute rhinosinusitis should be included in the differential diagnosis includes one major factor, or two or more minor factors. In absence of other nasal factors, fever or pain alone does not constitute a strong history. Severe, prolonged, or worsening infections may be associated with a nonviral element. Factors suggesting acute bacterial sinusitis are the worsening of the symptoms after ﬁve days, the persistence of symptoms for more than 10 days, or the presence of symptoms out of proportion to those typically associated with viral URTI.

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2. Subacute rhinosinusitis represents a continuum of the natural progression of acute rhinosinusitis that has not resolved. This condition is diagnosed after a four-week duration of acute rhinosinusitis, and it lasts up to 12 weeks. Patients with subacute rhinosinusitis may or may not have been treated for the acute phase, and the symptoms are less severe than those found in acute rhinosinusitis. Thus, unlike in acute rhinosinusitis, fever would not be considered as a major factor. The clinical factors required for the diagnosis of subacute adult rhinosinusitis are the same as for those CRS. Subacute rhinosinusitis usually resolves completely after an effective medical regimen. 3. Recurrent acute rhinosinusitis is deﬁned by symptoms and physical ﬁndings consistent with acute rhinosinusitis, with these symptoms and ﬁndings worsening after ﬁve days or when persisting more than 10 days. However, each episode lasts 7 to 10 days or more, and may last up to four weeks. Furthermore, four or more than four episodes occur in one year. Between episodes, symptoms are absent without concurrent medical therapy. The diagnostic criteria for recurrent acute rhinosinusitis are otherwise identical to those of acute rhinosinusitis. 4. Chronic rhinosinusitis is rhinosinusitis lasting more than 12 weeks. The diagnosis is conﬁrmed by the major and minor clinical factor complex (Table 4) with or without ﬁndings on the physical examination. A strong history consistent with chronic rhinosinusitis includes the presence of two or more major factors, or one major and two minor factors. A history suggesting that CRS should be considered in the differential diagnosis includes two or more minor factors or one major factor. Facial pain does not contribute a strong history in the absence of other nasal factors. 5. Acute exacerbation of chronic rhinosinusitis represents sudden worsening of the baseline CRS with either worsening or new symptoms. Typically the acute (non-chronic) symptoms resolve completely between occurrences. The advantage of the TFR classiﬁcation (5) over the Princeton meeting classiﬁcation (23) is that no CT scan is needed, and the diagnosis is made on clinical grounds only (i.e., major and minor factors and duration). Williams et al. demonstrated that the overall clinical impression that takes into account 16 historical items is more accurate than a single physical examination in predicting the presence of rhinosinusitis (28). Another advantage of the TFR guidelines is that they do not include nasal endoscopy or radiological imaging, and so they are not only applicable to the specialist but also to the primary care physician. Kenny et al. (29) and Duncavage (30), in a prospective study at the Vanderbilt Asthma Sinus and Allergy Program evaluating the AAO-HNS guidelines, found that the severity of

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sinus pain/pressures and sinus headache did not correlate with CT scan ﬁndings. On the other hand, the severity of ﬁve other symptoms (fatigue, sleep disturbance, nasal discharge, nasal blockage, and decreased sense of smell), either alone or in combination, correlated with the severity of the CT scan ﬁndings of sinusitis. In another study, Orlandi et al. presented their experience with the TFR guidelines in diagnosing chronic rhinosinusitis and reevaluated these guidelines three years after publication (31). They found that these criteria provide a relatively sensitive (88%) working deﬁnition of chronic sinusitis in a patient population scheduled for surgery. Nasal obstruction/blockage and facial congestion/fullness were the most common symptoms. Their ‘‘gold standard’’ for the deﬁnition of chronic sinusitis is a patient who has symptoms for more than 12 weeks, evidence of rhinosinusitis that was discovered on CT, and an inﬂammation that was found on the analysis of pathology specimens. Hwang et al. (32) found a poor agreement between the rhinosinusitis TFR set forth positivity of symptoms—based on diagnostic guidelines for CRS—and the CT scan positivity. The sensitivity of the TFR criteria for detecting a positive scan was 89%, but the speciﬁcity was poor at only 2%. Finally, Stankiewicz et al. compared 78 patients that met the TFR criteria of subjective diagnosis with CT scan ﬁndings and endoscopy (Table 5) (33). They found that in 78 patients with a positive subjective diagnosis based on the TFR criteria, 53% had a negative CT scan and 45% had a negative endoscopy and a negative CT scan. When they looked at the number of patients with negative endoscopy and negative CT scans, and negative endoscopy and minimal disease on the CT scan, then endoscopy was correlated with CT scanning in about 80% of the patients. However, the sensitivity and speciﬁcity of endoscopy versus CT scan were 74% and 84%, respectively. On a cost-analysis basis, they conclude that endoscopy performed by a specialist should be used to corroborate the diagnosis. According to these authors, an evidence-based and reliable subjective symptom score correlating better with endoscopy and CT scan is needed (33).

Table 5 Total Patients in the Study Fulﬁlling the TFR Criteria for the Subjective Diagnosis of Chronic Rhinosinusitis n ¼ 78 (100%) CT scan positive for rhinosinusitis CT scan negative for rhinosinusitis Endoscopy positive, CT positive Endoscopy positive, CT negative Endoscopy negative, CT positive Endoscopy negative, CT negative Negative endoscopy correlated with CT Source: Adapted from Ref. 33.

47% 53% 22% 8% 26% 45% 65%

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Bhattacharyya (34) stated that the scientiﬁc basis for grouping major and minor symptoms in the TFR guidelines was not clear. According to the author, criteria justifying the classiﬁcation of a symptom as ‘‘major’’ could include a higher prevalence in patients with CRS, a higher severity level, or an increased speciﬁcity of the symptom for the diagnosis of CRS. In a prospective study of 120 patients with CRS, the major symptoms of CRS were both more prevalent and manifest to a more severe degree than in patients without CRS. Fatigue, considered by the guidelines to be a minor symptom, was a more common and severe symptom manifestation of CRS in the patient population. When looking at the anatomical symptom domains [nasal (nasal obstruction, rhinorrhea, and sense of smell), facial (facial pain/pressure, facial congestion/fullness, and headache), oropharyngeal (halitosis, dental pain, and cuff and ear symptoms), and systemic], they found that the nasal and paranasal symptoms were the most likely manifestations to be found in patients with CRS. Finally, in 1998 (13), part of the Joint Task Force on Practice Parameters representing the American Academy of Allergy, Asthma and Immunology, The American College of Allergy, Asthma and Immunology, and the Joint Council of Allergy, Asthma and Immunology, deﬁned sinusitis as an inﬂammation of one or more of the paranasal sinuses, but they immediately add that the most common cause of sinusitis is infection. In their deﬁnition, the borderline between acute and chronic depends on the clinician and extends from three weeks to eight weeks. It is obvious from all these classiﬁcations and deﬁnitions that there still exists a controversy between the duration of acute and chronic sinusitis and the use of the term subacute sinusitis. If the term subacute sinusitis is not used, the duration of chronic sinusitis in the adult population is deﬁned to be more than eight weeks (23); if the term subacute is used, the duration is more than 12 weeks (TFR guidelines) (5). One of the reasons the TFR guidelines reintroduced the concept of subacute sinusitis is that a duration of 8 to 12 weeks for the term acute sinusitis was considered to be too long, whereas a duration of no more than four weeks seemed to be more appropriate. The TFR of the AAO-HNS states that their deﬁnitions were based on an amended list of the major and minor clinical symptoms and signs believed to be most signiﬁcant for the accurate clinical diagnosis of all forms of adult rhinosinusitis (5). Anterior rhinoscopy performed in the decongested nose revealed hyperemia, edema, crusting, polyps, and/or, most signiﬁcantly, purulence in the nasal cavity. This statement is of importance because it included the presence of nasal polyps or nasal polyposis in the deﬁnition of CRS. Hadley et al., also a members of the TFR, stated when discussing clinical evolution of rhinosinusitis, that CRS may predispose patients to nasal polyposis, which aggravates hyposmia and may lead to anosmia. This statement supports the opinion of several authors (35) who view nasal

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polyposis as a subgroup of CRS. However, the lack of a good deﬁnition of nasal polyps or nasal polyposis makes utilization of this deﬁnition difﬁcult. According to Stedman’s Medical Dictionary, a polyp is a general descriptive term with reference to any mass of tissue that bulges or projects outwards or upwards from the normal surface level, thereby macroscopically visible as a hemispheroidal, spheroidal, or irregular mound-like structure, growing from a relatively broad base or a slender stalk (36). Dorland deﬁnes a polyp as a morbid excrescence or protruding growth from mucous membrane, classically applied to a growth on the mucous membrane of the nose (37). This means that any spheroidal outgrowth of the nasal mucosa in the nose or the paranasal sinuses is to be considered a nasal polyp. Some authors, however, consider chronic sinusitis and nasal polyposis as different diseases of the respiratory mucosa of the paranasal sinuses (38). They deﬁne every polyp that can be seen by endoscopy as nasal polyposis and any polyp in the sinuses as hyperplasia. Ponikau stated that, in the Mayo Clinic, they consider nasal polyposis the end stage of the chronic inﬂammation process of chronic rhinosinusitis rather than two different diseases (39). According to these authors, CRS is an inﬂammatory disease of the nasal and paranasal sinuses that is present for more than three months, and is associated with inﬂammatory changes ranging from polypoid mucosa thickening to gross nasal polyps. Orlandi et al. were not able to see a signiﬁcant difference between the number of major and minor factors of patients with or without nasal polyps (31). They only found that nasal dryness/crusting (not a TFR factor) was more prevalent in patients with nasal polyposis. Also, the Sinus and Allergy Health Partnership Taskforce (SAHP) described that one of the signs of inﬂammation must be present and identiﬁed in association with ongoing symptoms [TFR guidelines (Table 4) (5)], consistent with CRS (40). The presence of discolored nasal drainage arising from the nasal passages, nasal polyps, or polypoid swelling as identiﬁed on a physical examination with anterior rhinoscopy or nasal endoscopy. Finally, in a position paper on rhinosinusitis and nasal polyps, the European Academy of Allergy and Clinical Immunology (EAACI) stated that chronic sinusitis is the primary disease and nasal polyposis is its subpopulation (41). According to Hamilos, (42) inﬂammation plays a key role in CRS. This author describes two types of inﬂammation that occur in sinusitis, contributing variably to the clinical expression of disease; those are the infectious inﬂammation that is most clearly associated with acute sinusitis, resulting from either bacterial or viral infection, and the noninfectious inﬂammation that is so named due to the predominance of the eosinophils and the mixed mononuclear cells, and relative paucity of neutrophils commonly seen in CRS. Mucosal thickening, sinus opaciﬁcation, and nasal polyposis are seen at both ends of the spectrum (43). In some, cases intensive treatment with antibiotics and a short course of prednisone caused nearcomplete resolution of mucosal thickening and sustained improvement of

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symptoms. Such cases represent the infectious end of the spectrum. In other cases, similar treatment causes minimal regression in mucosal thickening or nasal polyposis, and minimal improvement in symptoms. Such cases can be considered as at the inﬂammatory end of the spectrum. Nasal polyps are most characteristic of noninfectious sinusitis but cannot be strictly categorized as infectious and noninfectious. Therefore, Hamilos (43) prefers the descriptive term ‘‘chronic hyperplastic sinusitis with nasal polyposis’’ or CHS/NP because it avoids implication of disease pathogenesis. CHS/NP has the following features: 1. 2. 3. 4.

Presence of chronic sinusitis Extensive bilateral mucosal thickening Nasal polyposis (usually bilateral) Without obvious underlying disease, such as hypogammaglobulinemia, cystic ﬁbrosis, or immotile cilia syndrome

In Hamilo’s experience (43), asthma and aspirin-sensitivity are associated with CHS/NP in 62% and 49%, respectively, of their patients. According to Hamilos (43), a distinguishing feature of mucosal pathology of CHS/NP is tissue eosinophilia that is accompanied by an inﬁltrate of mononuclear cells, T cells, and plasma cells, neutrophilia being uncommon, occurring in only 25% of nasal polyps (44). THE CLASSIFICATION OF FUNGAL SINUSITIS Ponikau et al. (45,46) conﬁrmed the presence of sinus eosinophilia in the majority (96%) of their patients with CRS by means of histological analysis of 101 consecutive patients. In the same study, they also found fungal organisms, as examined on the basis of culture (96% of patients) and histology (81%), in the sinus mucus of patients with CRS, suggesting that these organisms might be involved in the disease process of CRS. However, to their surprise, fungal organisms were also detected in the nasal mucosa of the majority of healthy control subjects. They concluded that the combination of eosinophilia and the presence of fungi explain the chronic inﬂammation in 96% of the patients with CRS. As further proof of their theory, Ponikau et al. (39,45) highlighted their observation that in 51 randomly selected patients given the diagnosis of CRS and treated with intranasal amphotericin B lavage, 75% experienced a signiﬁcant improvement of nasal symptoms, especially nasal discharge and nasal obstruction and 36% had a polyp-free nasal endoscopy. In those where a control CT scan was performed, they observed an improvement of the sinus opaciﬁcation. The authors admit that the potential weakness of their pilot study is the fact that they did not include a placebo group. The statement of the Ponikau group from the Mayo Clinic that the majority of the CRS cases are caused by an abnormal eosinophilic response of the patient

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to fungi initiated an intense controversy about the validity of the fungal hypothesis (see the following sections). In 1976, Saﬁrstein (47) described a 24-year-old woman with allergic bronchopulmonary aspergillosis (ABPA) associated with nasal obstruction, nasal polyps, and nasal cast formation. Millar et al. (48) and Katzenstein et al. (49) mentioned the histological similarity between sinus mucoid material and mucoid impaction of the bronchi in patients with ABPA, and they named it ‘‘allergic aspergillus of the maxillary sinus’’ and ‘‘allergic aspergillus sinusitis,’’ respectively. The latter (49) described the typical mucincontaining numerous eosinophils, sloughed respiratory cells, cellular debris, Charcot-Leyden crystals, and scattered fungal hyphae resembling Aspergillus species. Waxman et al. (50) described the clinical features of a young adult patient with allergic aspergillus sinusitis, showing a history of asthma and recurrent polyposis, radiographic evidence of pansinusitis, and the typical mucinous material as described by Katzenstein et al. (49). The majority of their patients had positive skin tests for Aspergillus (60%), 85% had IgE serum levels, and 85% had precipitins to Aspergillus. Robson et al. (51) introduced the term ‘‘allergic fungal sinusitis’’ (AFS) after they described a case of an expansive tumor of the paranasal sinus caused by the rare fungal pathogen Bipolaris hawiiensis. Corey et al. (52) stressed the importance of the host’s immunological status, local tissue condition, and histopathological examination to differentiate among different forms of fungal disease. They differentiate between: 1. Allergic fungal sinusitis as the sinus counterpart of ABPA; patients showing chronic sinusitis can be atopic and show elevated IgE levels and eospinophilic counts in the peripheral blood. 2. Fungal ball or aspergilloma due to massive fungal exposure or local tissue anoxia. Patients are not immunocompromised. 3. Invasive or fulminent fungal sinusitis occurring in immunocompromised patients. Other authors (53) also deﬁne AFS (previously allergic aspergillus sinusitis) as a chronic sinusitis with nasal polyposis in young immunocompetent patients, showing diffuse expansive sinus disease on CT scan, with the typical allergic mucine described earlier. All their patients had positive IgE RAST to fungal antigens. Taking into account the immune status of the patient, Bent et al. (54) categorize fungal sinusitis into ﬁve subgroups: the role of the fungi, the presence of tissue invasion, the cause, and the affected sinus. A similar classiﬁcation for fungal sinusitis was already published earlier by Ence et al. (55). 1. Invasive fungal sinusitis is an acute fungal sinusitis affecting one sinus in an immunocompromised patient, showing tissue invasion.

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2. Indolent fungal sinusitis is a subacute sinus infection with variable tissue invasion of one or more sinuses in a nonatopic immunocompetent patient. 3. Mycetoma or fungal ball is a chronic saprophytic sinusitis of one sinus without tissue invasion in a non-atopic immunocompetent patient. 4. AFS is a chronic fungal sinusitis in an immunocompetent atopic patient, where the fungus acts as an allergen involving multiple sinuses with a unilateral predominance without tissue invasion. The patient must demonstrate the characteristic allergic mucine and have evidence of fungal etiology, either by direct observation in the surgical specimen, or by recovery of the organism in cultures of the sinus content. 5. AFS like syndrome: these patients have the same features as AFS patients, however, without the presence of fungi. Cody et al. (56) found that 40% of these patients with allergic mucin have AFS-like syndrome. Ferguson (57) named this AFS-like syndrome ‘‘Eosinophilic Mucin Rhinosinusitis’’ (EMR) stating that the driving force is not a fungus but a systemic dysregulation associated with upper and lower eosinophilia. In 1995, deShazo et al. (58) described the criteria for the diagnosis of AFS in his study as follows: 1. Sinusitis of one or more paranasal sinuses on x-ray ﬁlm 2. Identiﬁcation of allergic mucin by rhinoscopy or at the time of the sinus surgery or subsequently on histopathological evaluation of material from the sinus 3. Documentation of fungal elements in nasal discharge or in material obtained at the time of surgery by stain or culture 4. Absence of diabetes, previous or subsequent immunodeﬁciency disease, and treatment with immunosuppressive drugs 5. Absence of invasive fungal disease at the time of diagnosis or subsequently From the criteria for the diagnosis of AFS listed by deShazo and Swain (58), for these authors absence of atopy, asthma, nasal polyps, elevated IgE levels, and serum fungal precipitins do not exclude the diagnosis of AFS. Furthermore, bilateral involvement of the sinus on x-ray examination does not exclude the diagnosis either. On the basis of immunopathological ﬁndings in ABPA and AFS, Corey et al. (59) concluded that both represent Gell and Coombs type I and type III response. In AFS, IgG antibodies, in addition to elevated IgE antibodies, to the speciﬁc fungus in the serum can be demonstrated. Therefore, they suggest the following immunological workup: total eosinophil

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count, total serum IgE, fungal antigen-speciﬁc IgE in vitro testing and/or skin test, fungal antigen-speciﬁc IgG (if available), and precipitating antibodies (if available). In 1998, Manning et al. (60) showed that AFS is an antigen, IgE-and IgG-mediated, hypersensitivity response with a late-phase eosinophilic inﬂammatory reaction. On the basis of immunohistocytochemistry studying major basic protein (MBP) eosinophil-derived neurotoxin (EDN) and a neutrophils mediator (neutrophils elastase) in tissue samples of CRS, they also showed that in all cases there was evidence that MBP and EDN mediatorrelease predominated over neutrophils elastase, proving that AFS is a predominantly eosinophilic-driven disease. In a controversial publication, Ponikau et al. (46) reevaluated the recurrent criteria for diagnosing AFS in CRS. By using a novel method of mucous collection and fungal-culturing technique, the authors demonstrated allergic mucin in 96% of 101 consecutive surgical cases of CRS. In the majority of their patients, they were not able to ﬁnd an IgE-mediated hypersensitivity to fungal antigens. Since the presence of eosinophils in allergic mucin, and not a type I hypersensitivity, was likely the common denominator in the pathophysiology of AFS, they proposed a change of terminology from AFS to ‘‘eosinophilic fungal rhinosinusitis (EFR).’’ Similar results were found by Braun et al. (61). Other authors had their doubts about the validity of the Mayo Clinic hypothesis (46). Marple (62) questioned whether fungi are indeed ubiquitous and are present within 100% of normal noses, and wondered what separates those patients who develop AFS from the normal population. He also questioned if the fungal screening methods used in the study were so sensitive that normal fungal colonization was mistaken for AFS, or if CRS merely represents an early form of clinically recognized AFS. Although it is generally accepted that eosinophils play an important role in the development of both AFS and some forms of CRS, the factors that ultimately trigger eosinophilic inﬂammation remain in question. Riechelmann et al. (63) disagree with the EFR theory. They were able to show the presence of fungi only in 50% of the patients with nasal polyposis when using the most sensitive detection techniques. Ragab et al. (64), using the same culture technique used by Ponikau et al. (46), were able to show positive fungal cultures in 44% of the middle meatal lavage and in 36% of the nasal cavity lavage of patients with CRS. It seems, therefore, that the rate of positive lavages is dependent of the site of collection of the sample. The question whether fungi are present in the upper airways inducing an eventual eosinophilic response may not be relevant because the presence of these fungi can be a mere epiphenomenon of an unknown cause that initially induced the CRS. The fungi may have not been adequately removed by the mucociliary clearance and ultimately resulted in an eosinophilic response.

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Novey et al. (65) showed that a normal person inhales about 50 million spores a day. With normal mucociliary clearance, these fungal spores are removed adequately and do not have the time to germinate and release their toxins. Once the fungi are not cleared because of an unknown cause, fungi start to colonize the sinuses and may contribute to the maintenance or ampliﬁcation of the disease. The therapeutical results with antifungal agents such as amphotericin B lavage (39,45) or nasal spray (66) do not strongly support the role of fungi in CRS, as only in 35% to 43%, respectively, of the nasal cavities become disease-free. Bernstein et al. (67), who are recently studying the molecular biology and immunology of nasal polyps, were unable to demonstrate that fungi play a principal role in CRS. Their data (67) support the hypothesis that Stapylococcus aureus releases a variety of enterotoxins (superantigens) in the nasal mucus that induce an interaction of antigen-presenting cells and lymphocytes, resulting in an up-regulation of inﬂammatory cells (lymphocytes and eosinophils) following an up-regulation of cytokines (TFN, IL1b, IL-4, and IL-5). Bachert et al. (68) described IgE antibodies to S. aureus enterotoxins in polyp tissue, linked to a polyclonal IgE production and aggravation of eosinophilic inﬂammation. A similar mechanism was described by Perez-Novo et al. (69) in aspirin-sensitive nasal polyposis patients. If this hypothesis proves to be true, then the classiﬁcation of fungal sinusitis needs to be reconsidered and the deﬁnitions redeﬁned. It also illustrates that the constancy of the classiﬁcations based on the hypothetical causes is not very reliable. Finally, Ferguson (57) described a visible growth of fungus (in AFS or EFR the fungus is not visible to the naked eye) within the nasal cavity of an asymptomatic individual and uses the term ‘‘saprophytic fungal infestation’’ for this condition.

THE CLASSIFICATION OF PEDIATRIC RHINOSINUSITIS During the last decade, three manuscripts have been published that classiﬁed pediatric rhinosinusitis (6,70,71). The Lusk et al. guidelines (70) were an extension of the TFR guidelines of the AAO-HNS (5) using the same classiﬁcations. The Clement report (6) consisted of an International Consensus Meeting (ICM), primarily of otorhinolaryngologists, and the Wald et al. (71) clinical practice guideline was a consensus of the Subcommittee on Management of Sinusitis and Committee on Quality Improvement of the American Academy of Pediatricians (SMS/CQI-AAP). The three classiﬁcations of pediatric rhinosinusitis are similar, and therefore, their deﬁnitions and classiﬁcation can be discussed together: 1. Acute rhinosinusitis in children is deﬁned as an infection of the sinuses mostly introduced by a viral infection, where complete

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Table 6 Symptoms of Severe and Non-severe Pediatric Rhinosinusitis Non-severe Rhinorrhea of any quality Nasal congestion Cough Headache, facial pain, and irritability (variable) Low grade or no fever

Severe Purulent rhinorrhea (thick, opaque, colored) Nasal congestion Peri-orbital edema Facial pain and headache High fever (39 C)

Source: From Ref. (6).

resolution of symptoms (judged on a clinical basis only) without intermittent URTI may take up to 12 weeks (ICM) (6). Acute sinusitis can be further subdivided into severe and nonsevere (Table 6). The SMS/CQI-AAP guideline (71) introduces the concept of acute bacterial rhinosinusitis (ABRS) complicating an acute viral rhinosinusitis. ABRS is an infection of the paranasal sinuses, lasting less than 30 days, in which symptoms resolve completely. According to Mucha et al. (72) the diagnosis of ABRS should be considered after a viral URI, when symptoms worsen after ﬁve days, are present for longer than 10 days, or are out of proportion to those seen with most viral infections. To cover the duration gap between acute and chronic, the SMS/ CQI-AAP guideline (71) also introduced the concept of ‘‘subacute bacterial sinusitis’’ in children as an infection of the paranasal sinuses lasting between 30 and 90 days in which symptoms resolve completely. The term subacute sinusitis was not recommended by the ICM (6) in Brussels, as the difference between acute and subacute is very arbitrary and it does not imply a different therapeutic approach in children. 2. Recurrent acute rhinosinusitis in children are episodes of the bacterial infection of the paranasal sinuses separated by intervals during which the patient is asymptomatic. According to the SMS/ CQI-AAP guideline (71), these episodes last less than 30 days and are separated by intervals of at least 10 days. 3. Chronic rhinosinusitis in children is deﬁned as a nonsevere sinus infection with low-grade symptoms that presents longer than 12 weeks. 4. Finally, recurrent acute rhinosinusitis in children has to be differentiated from chronic rhinosinusitis with frequent exacerbations (ICM) (6) or acute bacterial sinusitis superimposed on chronic

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sinusitis (SMS/CQI-AAP) (71). These are patients with residual respiratory symptoms who develop new respiratory symptoms. When treated with antimicrobials, these new symptoms resolve, but the underlying residual symptoms do not. The members of the ICM noted that medical treatment such as antibiotics and nasal steroids may modify symptoms and signs of acute and CRS, and it is sometimes difﬁcult to differentiate infectious rhinosinusitis from allergic rhinosinusitis in a child on clinical grounds alone. According to the SMS/CQI-AAP, a viral infection in children induces a diffuse mucositis and predisposes to a bacterial infection of the sinuses in 80% of cases whereas in 20% of the cases an allergic inﬂammation is responsible for the bacterial superinfection. In conclusion, an internationally well-accepted classiﬁcation of rhinosinusitis in adults as well as in children that is based on duration of signs and symptoms exists. However, there still exists much controversy concerning the classiﬁcation of fungal sinusitis. This classiﬁcation is controversial because it is based on the eventual cause of CRS, which is still not well understood. REFERENCES 1. Douek E. Acute sinusitis. In: Ballentyne J, Groves J, eds. Scott-Brown’s Diseases of the Ear, Nose and Throat, 3rd ed. The Nose. London: Butterworths, 1972:183–213. 2. Shapiro GG, Rachelefsky GS. Introduction and deﬁnition of sinusitis. J Allergy Clin Immunol 1992; 90:417–418. 3. Johnson JT, Ferguson BJ. Infection. In: Cummings CW, Fredrickson JM, Harker LA, Krause CJ, Richardson MA, Schuller DE, eds. Otolaryngology Head and Neck Surgery. Vol. 2. 3rd ed. St Louis: Mosby, 1998:1107–1108. 4. Lund VJ, Kennedy DW, Draf W, Friedman WH, Gwaltney JM, Hoffman SR, Huizing EA, Jones JK, Lusk RP, MacKay IS, Moriyana H, Nacleirio RM, Stankiewicz JA, van Cauwenberge P, Vining EM. Quantiﬁcation for staging sinusitis. Ann Otol Rhinol Laryngol 1995; 104(suppl 167):17–22. 5. Lanza D, Kennedy DW. Adult rhinosinusitis deﬁned. Otolaryngol Head Neck Surg 1997; 117:S1–S7. 6. Clement PAR, Bluestone CD, Gordts F, Lusk RP, Otten FWA, Goossens H, Scadding GK, Takahashi H, van Buchem L, van Cauwenberge P, Wald ER. Management of rhinosinusitis in children. Arch Otolaryngol Head Neck Surg 1998; 124:31–34. 7. Havas TE, Motbey JA, Gullane PJ. Prevalence of incidental abnormalities on computed tomographic scans of the paranasal sinuses. Arch Otolaryngol Head Neck Surg 1988; 114:856–859. 8. Bolger WE, Butzin CA, Parsons DS. Paranasal sinus bony anatomic variations and mucosal abnormalities CT analysis for endoscopic sinus surgery. Laryngoscope 1991; 101:56–64.

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9. Diament MJ, Senac MO, Gilsanz V, Baker S, Gillespie T, Larsson S. Prevalence of incidental paranasal sinuses opaciﬁcation in pediatric patients: a CT study. J Comput Assist Tomogr 1987; 3:426–436. 10. Gordts F, Clement PAR, Buisseret Th. Prevalence of sinusitis signs in a nonENT population. ORL 1996; 58:315–319. 11. Gordts F, Clement PAR, Destryker A, Desprechin B, Kaufman L. Prevalence of sinusitis signs on MRI in a non-ENT pediatric population. Rhinology 1997; 35:154–157. 12. Pinheiro AD, Facer GW, Kern EB. Sinusitis: current concepts and management. In: Bailey BJ, Calhoun KH, eds. Head and Neck Surgery–Otolaryngology. Vol. 1. 2nd ed. Philadelphia, New York: Lippincott-Raven, 1998:441–445. 13. Spector SL, Bernstein IL, Li JT, Berger WE, Kaliner MA, Schuller DE, Blessing-Moore J, Dykewicz MS, Fineman SF, Lee RE, Nicklas RA. Complete guidelines and references. Parameters for the Management of Sinusitis. Supplement to J Allergy Clin Immunol 1998; 102:S117–S124. 14. Kern EB. Sinusitis. J Allergy Clin Immunol 1984; 73:25–31. 15. McNab J. The Caldwell-Luc and allied operations. In: Dudley H, Carter D, Nose and Throat Consultant editor Ballantyne JC, Harrison DFN, eds. Rob and Smith’s Operative Surgery. 4th ed. London: Butterworths, 1986:116–120. 16. Wigand ME. Transnasale, endoscopische Chirurgie der Nasennebenho¨hlen bei Chronische Sinusitis. I. Ein bio-mechanisches Konzept der Schleimhautchirurgie. HNO 1981; 29:215–221. 17. Wigand ME. Transnasale, endoscopische Chirurgie der Nasennebenho¨hlen bei Chronische Sinusitis. II. Die endonasale Kieferho¨hlen Operation. HNO 1981; 29:263–269. 18. Reilly JS. The sinusitis cycle. Otolaryngol Head Neck Surg 1990; 103:856–862. 19. Mygind M. Perennial rhinitis. In: Mygind M, ed. Nasal Allergy. Oxford: Blackwell Scientiﬁc Publications, 1987:224–232. 20. Iwens P, Clement PAR. Sinusitis in allergic patients. Rhinology 1994; 32:65–67. 21. Gwaltney JM, Philips CD, Miller RD, Riker DK. Computed tomographic study of the common cold. N Eng J Med 1994; 330:25–30. 22. Leopold DA, Stafforrd CT, Sod EW, Szeverenyi NM, Allison JD, Phipps RJ, Juhlin KD, Welch MB, Saunders C. Clinical course of acute maxillary sinusitis documented by sequential MRI scanning. Am J Rhinol 1994; 8:19–28. 23. Kennedy DW. Sinus disease. Guide to ﬁrst-line management. In: Kennedy DW, ed., Health Communications. Intermedia Partners, 1994:1–44. 24. Lund VJ, Gwaltney J Jr, Baquero F, Echols R, Kennedy D, Klossek J-M, MacKay I, Mann W, Ohnishi T, Stammberger H, Vinig E, Wald E, Burridge SM. Infectious rhinosinusitis in adults: classiﬁcation, etiology and management. ENT J 1997;12(suppl 76):1–22. 25. Evans FO Jr, Sydnor JB, Moore WE, Moore GR, Manwaring JL, Brill AH, Jackson RT, Hanna S, Skaar JS, Holdeman LV, Fitz-Hugh S, Sande MA, Gwaltney JM Jr. Sinusitis of the maxillary antrum. N Engl J Med 1975; 293:735–739. 26. Gwaltney JM Jr, Scheld M, Sande MA, Sydnor A. The microbial etiology and antimicrobial therapy of adults with acute community-acquired sinusitis: a

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Clement ﬁfteen-year experience at the University of Virginia and review of other selected studies. J Allergy Clin Immunol 1992:457–462. Senturia BH, Bluestone CD, Lim DJ. Report of the Committee on deﬁnitions and classiﬁcations of otitis media and otitis media with effusion. Am Otol Rhinol Laryngol 1980; (suppl 68):89. Williams JW Jr, Simel DL, Roberts L, Samsa GP. Clinical evaluation of sinusitis. Making the diagnosis by history and physical examination. Ann Intern Med 1992; 117:705–710. Kenny TJ, Duncavage J, Bracikowski J, Yildirim A, Murray JJ, Tanner SB. Prospective analysis of sinus symptoms and correlation with paranasal computed tomographic scan. Otolaryngol Head Neck Surg 2001; 125:40–43. Duncavage JA. Rhinosinusitis, Editorial Commentary. Curr Opin Otorlaryngol Head Neck Surg 2001; 9:1–2. Orlandi RR, Terrell JE. Analysis of the adult chronic rhinosinusitis working deﬁnition. Am J Rhinol 2002; 16:7–10. Hwang PH, Irwin SB, Griest SE, Caro JE, Nesbit G. Radiologic correlates of symptom-based diagnostic criteria for chronic rhinosinusitis. Otolaryngol Head Neck Surg 2003; 128:489–196. Stankiewicz JA, Chow JM. Cost analysis in the diagnosis of chronic sinusitis. Am J Rhinol 2003; 17:139–142. Bhattacharyya N. The economic burden and symptoms manifestations of chronic rhinosinusitis. Am J Rhinol 2003; 17:27–32. Hadley JA, Schaefer SD. Clinical evaluation of rhinosinusitis: history and physical examination. Otolaryngol Head Neck Surg 1997; (suppl 117):S9–S11. Stedman’s Medical Dictionary. 26th ed. Baltimore: Williams and Wilkins, 1995:1405. Dorland’s Illustrated Medical Dictionary. 25th ed. Philadelphia: Saunders WB, 1965:1235. Watelet J-P, Gevaert P, Bachert C, Holtappels G, van Cauwenberge P. Secretion of TGF-B1, TGF-B2, EGF and PDGF into nasal ﬂuid after sinus surgery. Eur Arch Otorhinolaryngol 2002; 259:234–238. Ponikau JU. Antifungal nasal washes for chronic rhinosinusitis: what’s therapeutic—the wash or the antifungal? J Allergy Clin Immunol 2003; 111: 1137–1139. Benninger MS, Ferguson BJ, Hadley JA, Hamilos DL, Jacobs M, Kennedy DW, Lanza DC, Marple BF, Osguthorpe JS, Stankiewicz JA, Anon J, Denneny J, Emanuel I, Levine H. Adult chronic sinusitis: deﬁnitions, diagnosis, epidemiology and pathophysiology. Otolaryngol Head Neck Surg 2003; 129:S1–S32. Fokkens W, Lund V, Bachert C, Clement P, Hellings P, Holmstrom M, Jones N, Kalogjera L, Kennedy D, Kowalski M, Malburborg H, Mullel J, Passali D, Stammberger H, Stierna P. EAACI Position paper on rhinosinusitis and nasal polyps. Allergy 2005; 60:583–601. Hamilos DL. Chronic sinusitis. J Allergy Clin Immunol 2000; 106:213–227. Hamilos DL. Non infectious sinusitis. Allergy Clin Immunol Int 2001; 13: 27–32. Hamilos DL, Leung DYM, Wood R, Meyers A, Stephens JK, Barkans J, Meng Q, Cunningham L, Bean DK, Kay AB, Hamid Q. Chronic hyperplastic sinusi-

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tis: association of tissue eosinophilia with mRNA expression of granulocytemacrophage colony-stimulating factor and interleukine-3. J Allergy Clin Immunol 1993; 92:39–40. Ponikau JU, Sherris DA, Kita H, Kern EB. Intranasal antifungal treatment in 51 patients with chronic rhinosinusitis. J Allergy Clin Immunol 2002; 110:862–866. Ponikau JU, Sherris DA, Kern EB, Homburger HA, Frigas E, Gaffey TA, Roberts GD. The diagnosis and incidence of allergic fungal sinusitis. Mayo Clin Proc 1999; 74:877–884. Saﬁrstein BH. Allergic bronchopulmonary aspergillosus with obstruction of the upper respiratory tract. Chest 1976; 70:788–790. Miller JW, Johnston A, Lamb D. Allergic aspergillosus of the maxillary sinus. Prod Scott Thor Soc 1981; 36:710. Katzenstein AL, Sale Sr, Greenberger PA. Pathologic ﬁndings in allergic aspergillus sinusitis. A newly recognized form of sinusitis. Am J Surg Pathol 1983; 7:439–443. Waxman JE, Spector JG, Sale SR, Katzenstein A-LA. Allergic aspergillus sinusitis: concepts in diagnosis and treatment of a new clinical entity. Laryngoscope 1987; 97:261–266. Robson JM, Hogan PG, Benn RA, Gatenby PA. Allergic fungal sinusitis presenting as a paranasal sinus tumour. Aust NZJ Med 1989; 19:351–353. Corey JP, Delsupehe KG, Ferguson BJ. Allergic fungal sinusitis: allergic, infectious or both. Otolaryngol Head Neck Surg 1995; 113:110–119. Manning SC, Mabry RL, Schaefer SD, Close LG. Evidence of IgE-mediated hypersensitivity in allergic fungal sinusitis. Laryngoscope 1993; 103:717–721. Bent JP, Kuhn FA. Diagnosis of allergic fungal sinusitis. Otolaryngol Head Neck Surg 1994; 111:580–588. Ence BK, Gourley DS, Jorgensen NL, Shagets FW, Parsons DS. Allergic fungal sinusitis. Am J Rhinol 1990:169–178. Cody DT, Neel BN, Fereiro JA, Roberts GD. Allergic fungal sinusitis: The Mayo Clinic experience. Laryngoscope 1994; 104:1074–1079. Ferguson BJ. Eosinophilic mucin rhinosinusitis: a distinct clinicopathologic entity. Laryngoscope 2000; 110:799–813. deShazo RD, Swain RE. Diagnostic criteria for allergic fungal sinusitis. J Allergy Clin Immunol 1995; 96:24–35. Corey JP, Romberger CF, Shaw G. Fungal disease of the sinuses. Otolaryngology 1990; 103:1012–1015. Manning SC, Holman M. Further evidence for allergic pathophysiology in allergic fungal sinusitis. Laryngoscope 1998; 108:1485–1496. Braun H, Buzina W, Freudenschuss K, Beham A, Stammberger H. Eosinophilic fungal rhinosinusitis: a common disorder in Europe? Laryngoscope 2003; 113:264–269. Marple BF. Allergic fungal rhinosinusitis: current theories and management strategies. Laryngoscope 2001:1006–1019. Riechelmann H. Pilze aund Polypen—Fakten und mythen. Laryngol Rhinol Otol 2003; 82:766–768. Ragab A, Clement P, Vincken W, Simones F, Nolard N. Fungal cultures of different parts of upper and lower airways in chronic rhinosinusitis 2004. In press.

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65. Novey HS. Epidemiology of allergic bronchopulmonary aspergillosis. Immunol Allergol N Am 1998; 18:641–653. 66. Lacroix J-S. Effects of antifungal local treatment on nasal polyposis.In: Mladina R, ed. Nasal Polyposis. Zagreb, Croatia: Croation Medical Association, 2002:42–44. 67. Bernstein JM, Ballow M, Schlievert PM, Rich G, Allen C, Dryja D. A superantigen hypothesis for the pathogenesis of chronic hyperplastic sinusitis with massive polyposis. Am J Rhinol 2003; 17:321–326. 68. Bachert C, van Zele T, Gevaert P, De Schrijver L, van Cauwenberge P. Superantigens and nasal polyposis. Curr Allergy Asthma Rep 2003; 3:523–531. 69. Perez-Novo CA, Kowalski ML, Kuna P, Ptasinska A, Johansson S, Bachert C. Asperin sensitivity and IgE antibodies to Staphylococcus aureus enterotoxins in nasal polyposis: studies on the relationship. Int Arch Allergy Immunol 2004; 133:257–260. 70. Lusk RP, Stankiewicz JS. Pediatric sinusitis. Otolaryngol Head Neck Surg 1997; 117:S53–S57. 71. Wald ER, Bordley WC, Darrow DH, Grimm KT, Gwaltney JM Jr, Marcy SM, Senac MO, Williams PV. Clinical practice guideline: management of sinusitis. Am Ac of Pediatrics, Subcommittee on management of sinusitis. Pediatrics 2001; 108:798–808. 72. Mucha SM, Baroody FM. Sinusitis update 2003. Curr Opin Allergy Clin Immunol 3:33–38.

3 Rhinosinusitis: Clinical Presentation and Diagnosis Michael S. Benninger and Joshua Gottschall Department of Otolaryngology–Head and Neck Surgery, Henry Ford Hospital, Detroit, Michigan, U.S.A.

INTRODUCTION It is a widely held assertion that the diagnosis of bacterial rhinosinusitis is made too often (1). This is due to the inherent difﬁculty in making an accurate diagnosis. Many diagnostic challenges exist when evaluating patients with presumed rhinosinusitis. Since the sinuses cannot be observed directly, the diagnosis is dependent upon the history of present illness and is often aided by nonspeciﬁc symptoms and physical examination. Primary care physicians are at a particular disadvantage as they do not have ready access to nasal endoscopy or antral puncture with ﬂuid analysis, which at times are helpful for establishing a diagnosis. Particularly challenging is differentiating between a self-limiting upper respiratory tract infection (URTI) or ‘‘common cold’’ and allergy from an acute bacterial rhinosinusitis (ABRS). The most common symptoms of rhinosinusitis include nasal congestion, purulent rhinorrhea, facial pressure or pain, and anosmia or hyposmia. These symptoms are not unique to rhinosinusitis and may be features of other inﬂammatory processes of the sinonasal tract. Frequently, a recent viral infection or underlying allergy precedes the development of ABRS, and thus makes the diagnosis of rhinosinusitis all the more difﬁcult. The current health care environment also poses inherent challenges for physicians. Reduced time per ofﬁce visit, direct advertising by pharmaceutical 39

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corporations, and expectations of patients or caregivers may result in a hasty diagnosis of rhinosinusitis and the inappropriate administration of antibiotics. Clearly, prescribing antibiotics for viral or nonbacterial illness is inappropriate. However, more serious consequences of this action include the promotion of bacterial resistance, mild-to-serious drug reactions, and increased health care costs. These inherent challenges, along with the difﬁculty of establishing an accurate diagnosis of rhinosinusitis, have contributed to the estimated US $5.8 billion in overall health care expenditures attributed to rhinosinusitis each year (2). Thus, the accurate diagnosis of rhinosinusitis in both the adult and pediatric populations cannot be overemphasized.

DEFINITIONS Sinusitis refers to an inﬂammatory process localized within one or more of the paranasal sinuses, whereas rhinitis is an inﬂammatory process within the nasal cavity. Since it is unusual for sinusitis to be present without a concurrent rhinitis, rhinosinusitis may be a more appropriate descriptor for this clinical disease process. Rhinosinusitis has recently been deﬁned as ‘‘a group of disorders characterized by inﬂammation of the mucosa of the nose and paranasal sinuses’’ (3). This deﬁnition has two important features: the understanding that rhinosinusitis is a group of disorders with a number of different potential etiologies, and that the hallmark is inﬂammation, whether that inﬂammation is caused by an infection or some other inﬂammatory process. In this chapter, ABRS will speciﬁcally refer to a bacterial infection of the sinonasal tract unless stated otherwise. Chronic rhinosinusitis (CRS) may be associated with a number of different disorders or pathogenic mechanisms. In order to facilitate the management of rhinosinusitis and to improve communication amongst health care professionals, deﬁnitions of rhinosinusitis for both the adult and pediatric age groups have been adopted. These deﬁnitions have been temporally related from the onset of symptoms and include ABRS, subacute bacterial rhinosinusitis, and CRS (Table 1). ABRS is deﬁned as a bacterial infection of the paranasal sinuses lasting less than Table 1 Rhinosinusitis: Deﬁnitions Duration of symptoms Acute bacterial rhinosinusitis (ABRS) Subacute bacterial rhinosinusitis Chronic rhinosinusitis (CRS) Source: Adapted from Ref. 12.

<30 days >30 and <90 days >90 days

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30 days. In general, the symptoms resolve completely. Symptoms persisting longer than 10 days or worsening after ﬁve days more likely due to ABRS. Subacute bacterial rhinosinusitis is a bacterial infection of the paranasal sinuses lasting between 30 and 90 days with a similar presentation as seen in acute rhinosinusitis. CRS has recently been redeﬁned as ‘‘a group of disorders characterized by inﬂammation of the mucosa of the nose and paranasal sinuses of at least 12 consecutive weeks’ duration’’ (3). Patients often have persistent residual respiratory symptoms such as rhinorrhea or nasal obstruction. Two additional categories of rhinosinusitis further describe patients based upon frequency of infection. Recurrent acute bacterial rhinosinusitis is deﬁned as multiple episodes of bacterial infection of the paranasal sinuses, each lasting for at least 7 to 10 days but less than 30 days, and separated by intervals of at least 10 days during which the patient is asymptomatic. Patients with recurrent acute bacterial sinusitis typically have four or more such infections per year. Acute exacerbation of chronic rhinosinusitis occurs when individuals with CRS develop new acute respiratory symptoms. When treated with antimicrobials, these new symptoms resolve, but the underlying chronic symptoms do not. True recurrent acute bacterial rhinosinusitis tends to be relatively infrequent. Patients that ﬁt this proﬁle are more likely to have recurrent viral URTIs or acute exacerbations of CRS rather than true recurrent acute rhinosinusitis. To facilitate the diagnosis of rhinosinusitis, it may be useful to consider whether the sinonasal infection is a result of primary or secondary factors. Rarely is any one factor the sole cause of rhinosinusitis. More commonly, multiple medical conditions or underlying disorders can be found, which often complicates treatment. Rhinosinusitis due to primary factors is typically found in otherwise healthy individuals. The pathology is limited to the sinonasal tract. Medical treatment of the acute infection or the surgical correction of mucous outﬂow obstruction generally results in resolution of symptoms and overall improvement. Rhinosinusitis due to secondary factors is less common. Rhinosinusitis in these individuals is a consequence of an underlying systemic disease process or condition, predisposing patients to the development of rhinosinusitis as well as other infections. Examples of secondary factors include aspirin intolerance (Sampter’s triad), immunodeﬁciency, primary ciliary dyskinesia, and cystic ﬁbrosis. Treatment of the systemic disorder, in general, results in reduction in severity or resolution of the rhinosinusitis. A list of causative factors associated with the development of rhinosinusitis is seen in Table 2. PATHOPHYSIOLOGY The pathophysiology of rhinosinusitis is multifactorial. However, regardless of etiology, the common basis for the development of sinus disease is often associated with mucous stasis due to osteomeatal obstruction and/or

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Table 2 Factors Predisposing to Bacterial Rhinosinusitis Primary (local) factors Viral URI Allergic/nonallergic rhinitis Anatomic obstruction Deviated septum Concha bullosa Paradoxic middle turbinate Maxillary dental disease Medication effects Rhinitis medicamentosa Cocaine Air pollution/irritants Gastroesphageal reﬂux disease Nasal polyposis Neoplasm

Secondary (systemic) factors Diabetes mellitus Inhalant/food allergies Immune deﬁciency HIV Hypogammaglobulinemia Iatrogenic Asthma ASA intolerance (sampter’s) Mucociliary disorders Primary ciliary dyskinesia Cystic ﬁbrosis Pregnancy Hypothyroidism Autoimmune Sarcoidosis Wegener’s granulomatosis

mucociliary dysfunction. Persistent obstruction results in decreased oxygen tension, reduced sinus pH, ciliary dysfunction, and negative pressure within the sinus cavity. Sneezing or nose blowing may cause a transient opening of the sinus drainage pathways. This, in addition to negative pressure within the sinus cavity, may result in the inoculation of pathogenic bacteria from the nasal cavity or nasopharynx into an otherwise sterile sinus cavity (4). An optimal environment for overgrowth is thereby achieved, resulting in rhinosinusitis. There has been a great interest in identifying pathways for the development of CRS. The inﬂammatory roles of bacteria and fungi, and the subsequent response by inﬂammatory cells and production of mediators of inﬂammation, have generated new thinking regarding the pathophysiology (3). A noninfectious inﬂammatory response as a result of bacterial or fungal colonization resembling ‘‘allergic or asthmatic’’ inﬂammation has been described. The resultant host inﬂammatory response with production of inﬂammatory cytokines may be the underlying cause of CRS. Of particular interest in this area are the roles of bacterial and fungal allergy, eosinophilic inﬂammation, bioﬁlms, and superantigens (3). RHINOSINUSITIS OR UPPER RESPIRATORY TRACT INFECTION? Rhinosinusitis is most often a sequela of an acute URTI (5). Viruses responsible for URTIs include rhinovirus, parainﬂuenza virus, inﬂuenza virus type A and B, coronavirus, respiratory syncytial virus, and adenovirus.

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Rhinovirus is implicated in approximately 50% of common colds (1). In addition to osteomeatal obstruction due to inﬂammation and edema, respiratory viruses may have a direct cytotoxic effect on the nasal cilia that may result in impaired mucociliary clearance long after resolution of the acute viral infection. Rhinovirus has also been shown to increase the adherence of pathogenic bacteria, such as Streptococcus pneumoniae and Hemophilus inﬂuenzae in the nasopharynx, increasing the likelihood of bacterial colonization and infection (6). In the United States, the incidence of acute respiratory illness due to the common cold is two–three/year in the adult with 0.5% to 2% progressing into an ABRS (7). Children on average have six to eight upper respiratory infections per year, with 5% to 10% progressing into ABRS (8). Due to this reason, children may be particularly susceptible to rhinosinusitis. The time from onset of symptoms was found to play an important role in differentiating URTI from rhinosinusitis. Most viral URTI will begin to improve within seven days and completely resolve by 10 days. Symptoms worsening after seven days or persisting for 10 days or more are highly suggestive of bacterial rhinosinusitis (1,9).

DIAGNOSIS OF RHINOSINUSITIS Clinical investigations regarding the diagnosis of rhinosinusitis have been difﬁcult until recently, due to a lack of consensus for the deﬁnition of rhinosinusitis. In 1996, the Rhinosinusitis Task Force of the American Academy of Otolaryngology–Head and Neck Surgery published general criteria for the diagnosis of rhinosinusitis (10). Diagnosis is based upon the time from onset of symptoms, as well as the number and type of symptoms present. Thus, the diagnosis of rhinosinusitis is dependent upon establishing a time frame for the disease and then applying clinical criteria to assure the diagnosis. History Individuals with rhinosinusitis may present with symptoms of nasal congestion, nasal discharge, facial pressure or pain, hyposmia, or anosmia. The pain of acute rhinosinusitis is typically a stabbing pain or ache, localized over the involved sinus. Thus, pain may provide a clue as to which sinus is involved (Table 3). Maxillary sinus pain may elicit infraorbital tenderness extending to the maxillary teeth and occasionally to the ear. Ethmoid pain is typically reported between the eyes and over the nasal dorsum. Frontal pain may present as headaches extending to the temple or occiput. Isolated sphenoid sinus pain may present with headache, particularly at the vertex of the skull. Headaches and facial pain are rarely associated with rhinosinusitis, unless a concomitant nasal symptom is present.

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Table 3 Pain and Associated Sinus Involvement Sinus Maxillary Ethmoid Frontal Sphenoid

Associated pain Infraorbital, maxillary teeth, referred otalgia Medial canthus, nasal dorsum Supraorbital, bitemporal, occipital Vertex of skull

Children with rhinosinusitis may have a different presentation compared to their adult counterparts. Since young children are unable to verbalize their complaints, they may present with irritability as their only symptom. Sinus pain is not a prominent feature; however, children may have nasal obstruction and purulent rhinorrhea. Cough is a feature that may be seen in children with rhinosinusitis, which is typically not seen with adults. It may occur during the day or night; however, the cough is particularly worse at night. Rhinosinusitis is the second most common cause of chronic cough in children (11). Other symptoms include foul breath, bronchial hyperresponsiveness, and periorbital edema. The periorbital edema is usually non-tender and is usually seen on the dependent side and is worse upon awakening. The symptoms of nasal congestion/obstruction, facial pressure/pain, nasal purulence or rhinorrhea, and anosmia/hyposmia are considered major symptoms. The presence of two major symptoms is sufﬁcient for the diagnosis of rhinosinusitis (12). Cough is a minor symptom in adults, but a major symptom when seen in children. Minor symptoms include headache, irritability, fever, halitosis, fatigue, dental pain, and ear pain. The presence of one major symptom and two minor symptoms is also sufﬁcient for the diagnosis of rhinosinusitis (Table 4) (12). Although symptoms and time-based criteria may be appropriate in making the diagnosis in ABRS, they have been insufﬁcient in CRS (3). A diagnosis of CRS is best made through a combination of symptoms and time-based criteria as in ABRS, but supported by nasal endoscopy or radiologic testing. A thorough history of present illness is required for all patients, particularly to identify the secondary causes of rhinosinusitis. Features of the history important when evaluating an individual for rhinosinusitis include presenting symptoms, onset and duration of symptoms, and associated comorbid disorders. A history of asthma, aspirin intolerance, nasal polyposis, and rhinosinusitis is consistent with the ASA intolerance syndrome (Sampter’s triad). This entity is difﬁcult to treat, with persistent bronchial hyperreactivity, despite treatment of rhinosinusitis. Immune deﬁciencies including HIV, common variable immune deﬁciency, and IgG and IgA hypogammaglobulinemia are associated with recurrent rhinosinusitis. Patients with a history of recurrent pneumonia, otitis media, sterility,

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Table 4 Factors Associated with the Diagnosis of Chronic Sinusitis Major factor Facial pain, pressure (alone does not constitute a suggestive history for rhinosinusitis in absence of another major symptom) Facial congestion, fullness Nasal obstruction/blockage Nasal discharge/purulence/discolored nasal drainage Hyposmia/anosmia Purulence in nasal cavity on examination Fever (acute rhinosinusitis only) in acute sinusitis alone does not constitute a strongly supportive history for acute in the absence of another major nasal symptom or sign

Minor factors Headache

Fever (all non-acute) Halitosis Fatigue Dental pain Cough Ear pain/pressure/fullness

Source: Adapted From Ref. 12.

and rhinosinusitis should be evaluated for primary ciliary dyskinesia. Patients with Kartagener’s syndrome present with primary ciliary dyskinesia, rhinosinusitis, situs inversus, and bronchiectasis. Perennial or seasonal allergies may present with symptoms such as nasal congestion, cough, and behavioral changes, which are seen in both allergic rhinitis and rhinosinusitis. It may be the underlying etiology in failed antimicrobial therapy directed at presumed rhinosinusitis. Symptoms and signs consistent with allergies include sneezing, clear nasal secretions, and itchy mucous membranes of the upper aerodigestive tract. Allergies can play a signiﬁcant role in recurrent acute and chronic rhinosinusitis. All patients should be evaluated for allergies when the history is elicited, with a focus on both food and inhalant allergies, such as dust mite, mold, dander, and pollen (13). There may be a history of rhinosinusitis coinciding with the allergy season. The tendency to have allergy is genetically determined and therefore is reﬂected in the family history. If one parent has a history of allergy problems, any child in that family has a 20% to 40% chance of having an allergic disease. If both parents have allergy problems, any child has a 50% to 70% chance of having allergic manifestations at some time in his/her life (14). In 13% of children with a negative allergy history, skin testing is nevertheless positive. This has prompted some to advocate formal allergy testing in all cases of CRS who failed medical treatment, and prior to proceeding with surgery (15). Appropriate allergy skin testing or in vitro tests (RAST, ELISA, and IgE) may be performed. In vitro tests for allergy are useful in young children who may not tolerate skin testing. Gastroesphageal reﬂux disease, or GERD, has been implicated as an underlying etiology of CRS, especially in children. Double lumen pH probe

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analysis of children with CRS has demonstrated esophageal reﬂux in 63% of patients and nasopharyngeal reﬂux in 32% (16). Seventy-nine percent of patients had improvement in CRS symptoms after medical treatment of GERD. In a separate study, 89% of patients initially deemed as candidates for sinus surgery avoided an operation after reﬂux treatment (17). Patients with a history of maxillofacial trauma may present with recurrent rhinosinusitis or CRS due to disruption or obstruction of the osteomeatal drainage pathways. Complete resolution of recurrent symptoms may require surgical correction of the anatomic obstruction. Occasionally mucosa may be trapped within the fracture line, resulting in the development of a mucocele or a mucopyocele and CRS. Nasal neoplasm, both benign and malignant, may be a cause of unilateral nasal symptoms and rhinosinusitis due to obstruction of the nasal cavity and sinus drainage pathways. Unilateral nasal polyposis unresponsive to corticosteroid therapy should raise the index of suspicion for a nasal neoplasm. Care must be taken to rule out CNS tissue prior to biopsy. Inﬂammatory nasal polyposis is seen in bilateral nasal cavities and responds well to systemic and topical corticosteroid therapy. They may result from chronic nasal inﬂammation, often associated with nasal allergies. Inﬂammatory polyposis often has the classic ‘‘water bag’’ appearance. Any child with nasal polyposis should be evaluated for cystic ﬁbrosis. Physical Examination Intranasal examination may provide clues for the diagnosis of rhinosinusitis. However, this is often nonspeciﬁc and thus greater emphasis is placed upon the aforementioned symptoms-driven diagnostic criteria. Intranasal examination is facilitated through the use of a nasal speculum, handheld otoscope, or nasal endoscopes, including ﬁber-optic and rigid types (Fig. 1). The examination of the mucosal linings of the symptomatic nose may demonstrate generalized rhinitis with erythema and edema. The inferior turbinates, often engorged, may limit visualization beyond the anterior aspect of the inferior turbinate. Topical decongestion with alpha-adrenergic agonist, such as oxymetazoline, permits an improved visualization of the middle turbinate and middle meatus. Nasal purulence may be seen along the ﬂoor of the nasal cavity. The color of the mucous is not a dependable sign to differentiate a bacterial infection from a viral URTI. Distinguishing between purulent-appearing nasal secretions from an infected sinus versus colonized stagnant secretions from the nasal cavity or chronic adenoiditis may also prove difﬁcult. However, purulence found within the middle meatus is highly suggestive of rhinosinusitis. Nasal polyposis may be seen, and should be characterized based upon its growth beyond the anatomic limits of the middle meatus. This may be useful to document response to therapy. Occasionally, differentiating a nasal polyp from the middle

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Figure 1 Tools for intranasal examination include nasal specula and mirror, otoscope, ﬁber-optic endoscope, and rigid telescope.

turbinate may be a source of confusion. Palpation of the structure after application of topical 2% pontocaine may reveal a ﬁrm, tender structure more consistent with that of the middle turbinate. Signiﬁcant anatomic causes of obstructed sinonasal drainage should be noted, including septal deviation or spurring, concha bullosa, and paradoxical middle turbinate. Occasionally, adequate assessment of the lateral nasal wall may be problematic. Percussion over the maxillary and frontal sinus may elicit tenderness, which is, however, largely nonspeciﬁc. Oral cavity examination may demonstrate an oro-antral ﬁstula, poor dentition, or dental abscess. Purulent drainage from the nasopharynx may be seen in the posterior oropharynx. In young children or adults with mental illness, a foreign body must be considered, especially in cases of unilateral purulent rhinorrhea. The drainage is usually foul-smelling. An otoscopic examination may demonstrate otitis media. Due to its communication with the nasopharynx via the eustachian tube, in children the middle ear may be considered a paranasal sinus. Children with rhinosinusitis may have an associated otitis media. If allergy is present, the patients may display allergic shiners and a supratip

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crease due to chronic wiping of the nose. Children may have the classic ‘‘adenoid facies’’ secondary to chronic nasal obstruction due to an enlarged adenoid. Diagnostic Aids A number of diagnostic aids may be helpful in conﬁrming or making the diagnosis of rhinosinusitis. An evidenced-based report by the Agency for Health Care Policy and Research suggested that ancillary tests and radiographs are not cost-effective in making the diagnosis, and are typically unnecessary in uncomplicated ABRS. Rather, a clinical diagnosis is preferred. In CRS, however, it is recommended that unless the diagnosis is clear from history and physical examination, conﬁrmation should be obtained either through nasal endoscopy, CT scanning, or plain sinus X-rays. The various tools that have been used to aid in the diagnosis and assessing the response to treatment will be discussed. Transillumination Transillumination of the frontal or maxillary sinus may suggest the presence of ﬂuid; however, it cannot differentiate between ﬂuid opaciﬁcation, tumor, and agenesis of the sinus. Also, evaluation of ethmoid and sphenoid sinuses is not feasible. The utility of transillumination in the diagnosis of rhinosinusitis is questionable and would not likely facilitate the diagnosis or treatment. Transillumination may have some value in conﬁrming the diagnosis or assessing the response to treatment, if it were positive at the onset of treatment and negative later. Since clinical response may be a better measure, transillumination has little value (18). Rigid or Flexible Endoscopy Rigid or ﬂexible endoscopy gives the diagnostician unparalleled access to the nose for the evaluation of the lateral nasal wall, which may otherwise not be possible on anterior rhinoscopy (Fig. 2). The anatomy of the middle meatus can be carefully evaluated. The presence of accessory ostia may be confused for the natural os. Small polyps or purulence within the middle meatus may be seen. Evaluation of the sphenoethmoidal recess is possible by directing a ﬁber-optic scope along the ﬂoor of the nose and then directing the tip 90 degrees cephalad (toward the top of the head). In children, evaluation of the nasopharynx may demonstrate chronic adenoiditis. Cultures may be taken from the middle meatus during rigid nasal endoscopy. Although culture of the sinus cavity itself is not obtained, a strong correlation between endoscopic culture of the middle meatus and antral puncture with culture has been reported. Endoscopically obtained cultures demonstrate a sensitivity of 85.7%, and a speciﬁcity of 90.6% when

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Figure 2 Intranasal examination using 0 rigid telescope with video documentation.

compared to sinus puncture (19–21). Culture of the nasal cavity in the absence of frank purulence will likely yield nasal ﬂora, and thus would not be useful. Although culture-directed therapy is ideal, treatment of uncomplicated cases of rhinosinusitis is presumptive, and is directed at S. pneumoniae, H. inﬂuenzae, and Moraxella catarrhalis. However, cultures should be considered in patients who have failed previous therapy, have a history of immunodeﬁciency, or have poorly controlled diabetes mellitus. Although the concordance between cultures obtained from antral puncture and those endoscopically obtained from the middle meatus appear promising, not enough evidence currently exists to recommend this technique over antral puncture. Sinus Aspiration and Culture Although sinus aspiration and culture are considered the gold standard for the diagnosis of rhinosinusitis, they are rarely indicated in uncomplicated cases. The cost, need for specialty referral, and discomfort experienced by the patient need to be considered. Although generally safe, sinus puncture has been associated with rare but serious complications, including tissue emphysema, air embolism of venous channels, vasovagal reactions, and soft tissue or bony infection (19). Although adult patients readily tolerate

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the procedure in an outpatient setting, children often require a general anesthetic. As previously stated, initial treatment of ABRS is presumptive, directed at the most commonly identiﬁed organisms (S. pneumoniae, H.Inﬂuenzae, M. catarrhalis) (1). The majority of cases of rhinosinusitis would likely resolve even without antibiotics. Positive cultures are recovered in only 50% to 60% of patients diagnosed with rhinosinusitis (7,19,20). The maxillary sinus is readily accessible through a canine fossa approach or via the inferior meatus. In children, an inferior meatal approach is preferred since it carries less risk to the dentition and orbit. This is performed under general anesthesia and often in conjunction with adenoidectomy. A sublabial, canine fossa sinus puncture is well tolerated, and can be performed in the ofﬁce setting with minimal morbidity. Commercial kits are readily available (Fig. 2). A specialist ﬁnds the procedure simple to perform and accurate results can be obtained as long as proper steps are taken to prevent contamination (Table 5). The aspirated ﬂuid should be noted for its gross appearance. Aerobic and anaerobic cultures as well as gram stain should be obtained. Fungal cultures can be obtained if the index of suspicion is high. Individuals with rhinosinusitis who have failed multiple courses of antibiotics and those with immune suppression should be considered for sinus aspiration and culture. Those individuals with infection extending to the orbit or threatened intracranial extension should be scheduled for emergency surgery. However, critically ill patients who are not operative candidates may tolerate sinus aspiration quite well. This procedure may prove to be therapeutic as well as diagnostic. Quantitative cultures may assist in identiﬁcation of the pathogenic organism from nasal ﬂora. The recovery of bacteria in a density of at least 104 colony-forming units (CFU)/mL is considered representative of a true infection (8). Also, the ﬁnding of at least one organism per high power ﬁeld on gram stain is signiﬁcant, and correlates with the recovery of bacteria in a density of 105 CFU/mL (8).

Table 5 Procedure for Maxillary Sinus Puncture Approach through the canine fossa or inferior meatus Prepare site with topical antiseptic (Betadine) Local (1% lidocaine/1:100,000 epinephrine) inﬁltrated with 27-gauge needle Trocar and catheter is inserted into maxillary sinus directed away from orbit Withdraw trocar and aspirate If no frank pus, inject 2 cc sterile saline into maxillary sinus and aspirate Therapeutic irrigation of maxillary sinus with 60 cc sterile saline Specimen sent for gram strain, aerobic, and anaerobic cultures

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Limitations of sinus aspiration include the inability to sample the sphenoid and ethmoid sinuses. Frontal sinus sampling would engender risk to the brain and would be inadvisable. Contamination by oral or nasal ﬂora may result in misleading results; however, quantitative cultures may prove more reliable. Imaging The role of imaging is discussed in detail in another chapter, and will only be brieﬂy described here. Plain sinus radiographs have long been used to aid in the diagnosis of rhinosinusitis. Given the poor sensitivity and speciﬁcity and the likelihood of abnormal ﬁndings even with a viral URTI, plain sinus radiographs have little value in ABRS. They have not been shown to be cost-effective (18). They may be helpful in conﬁrming the diagnosis of CRS in patients who have appropriate signs and symptoms for a sufﬁcient duration of time, but cannot be conﬁrmed by a nasal examination, particularly where endoscopy is not available (3). Ultrasound has also been used, particularly in Europe, but has similar if not greater limitations compared to plain sinus ﬁlms (18). CT scanning is considered the radiographic modality of choice. Although limited in differentiating ABRS from a viral URTI (22), CT scans are very useful in CRS (3) or in assessing the suspected complications of either ABRS or CRS. MRI scan is generally considered to be of limited value in the evaluation of rhinosinusitis at this time (3). Ancillary Tests There are a number of ancillary tests that may be helpful in assessing the severity of disease or the response to treatment. These include measures of smell (such as the University of Pennsylvania Smell Identiﬁcation Test or UPSIT), measures of nasal airﬂow or resistance by acoustic rhinometry or rhinomanometry, the Electronic Nose, or various blood tests. As mentioned previously, allergy testing may be useful, particularly in those with a strong allergic history or family history, or who have had a poor response to directed therapy. Outcome Evaluations An area of great recent interest in many diseases and disorders over the last few years are the methods to evaluate quality of life (QOL) and outcomes. Rhinosinusitis has been well studied in relationship to QOL and outcomes, and a few tools or instruments have been speciﬁcally designed to evaluate this speciﬁc entity. Three commonly used instruments are the Rhinosinusitis Disability Index (RSDI) (23), the Sino–Nasal Outcomes Test (SNOT) (24), and the Chronic Sinusitis Survey (CSS) (25). The RSDI was speciﬁcally developed to assess rhinosinusitis, although it has more recently been validated for other nasal and sinus disorders, including allergic and non-allergic rhinitis. Although there are some differences between these

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instruments, they all serve to establish a level of function for rhinosinusitis patients and may be used to evaluate the response to treatment. CONCLUSION Many symptoms of rhinosinusitis are common to other nasal inﬂammatory diseases such as the common cold and seasonal or perennial allergy. The diagnosis of both pediatric and adult rhinosinusitis is best made based upon clinical criteria (3), with a large portion of the diagnosis being based upon the duration of symptoms into acute, subacute, and chronic subtypes. The duration of symptoms is supported by the number and type of symptoms as well as physical ﬁndings. Thus, the diagnoses are dependent upon establishing a time frame for the disease and then applying clinical criteria to assure the diagnosis. Ancillary diagnostic evaluation should be considered on a case-by-case basis. However, nasal endoscopy or CT scan should be part of the diagnostic evaluation of CRS. Culture-directed therapy is not cost-effective in cases of routine ABRS and is not recommended. The physician should rely on the understanding of the pathophysiology and natural history of rhinosinusitis to make an accurate diagnosis and institute an appropriate treatment plan. REFERENCES 1. Sinus and Allergy Health Partnership. Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Otolaryngol Head Neck Surg 2004; 130(suppl 1): S1–S50. 2. Ray NF, Baraniuk JN, Thamer M, Rinehart CS, Gergen PJ, Kaliner M, Josephs S, Pung YH. Healthcare expenditures for sinusitis in 1996: contributions of asthma, rhinitis, and other airway disorders. J Allergy Clin Immunol 1999; 103:408–414. 3. Benninger MS, Ferguson BJ, Hadley JA, Hamilos DL, Jacobs M, Kennedy DW, Lanza DC, Marple BF, Osguthorpe JD, Stankiewicz JA, Anon J, Denneny J, Emanuel I, Levine H. Adult chronic rhinosinusitis: deﬁnitions, diagnosis, epidemiology, and pathophysiology. Otolaryngol Head Neck Surg 2003; 129(3): S1–S32. 4. Benninger MS, Anon J, Mabry RL. The medical management of rhinosinusitis. Otolaryngol Head Neck Surg 1997; 117:S41–S49. 5. Kaliner M. Medical management of sinusitis. Am J Med Sci 1998; 316(1):21–28. 6. Fainstein V, Musher DM, Cate TR. Bacterial adherence to pharyngeal cells during viral infection. J Infect Dis 1980; 141(2):172–176. 7. Gwaltney JM. Acute community-acquired sinusitis. Clin Infect Dis 1996; 23: 1209–1225. 8. Wald ER. Sinusitis. Pediatr Rev 1993; 14(9):345–351. 9. American Academy of Pediatrics. Subcommittee on Management of Sinusitis and Committee on Quality Improvement. Clinical practice guideline: management of sinusitis. Pediatrics 2001; 108(3):798–808.

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10. Anon JB. Report of the rhinosinusitis task force committee meeting: alexandria, Virginia, August 17th, 1996. Otolaryngol Head Neck Surg 119;117(3 Pt 2): S1–S68. 11. Holinger LD. Chronic cough in infants and children. Laryngoscope 1986; 96: 316–322. 12. Lanza DC, Kennedy DW. Adult rhinosinusitis deﬁned. Otolaryngol Head Neck Surg 1997; 117:S1–S7. 13. Goldsmith AJ, Rosenfeld RM. Treatment of pediatric sinusitis. Pediatr Clin North Am 2003; 50:413–426. 14. Cook PR, Nishioka GJ. Allergic rhinosinusitis in the pediatric population. Otolaryngol Clin North Am 1996; 29:29–56. 15. Parsons DS. Chronic sinusitis: a medical or surgical disease? Otolaryngol Clin North Am 1996; 29(1):1–9. 16. Phipps CD, Wood WE, Gibson WS, Cochran WJ. Gastroesophageal reﬂux contributing to chronic sinus disease in children. Arch Otolaryngol Head Neck Surg 2000; 126:831–836. 17. Bothwell MR, Parsons DS, Talbot A, Barbero GJ, Wilder B. Outcome of reﬂux therapy on pediatric chronic sinusits. Otolaryngol Head Neck Surg 1999; 121:255–262. 18. Benninger MS, Holzer S, Lau J. Diagnosis and treatment of acute bacterial rhinosinusitis: summary of the Agency on Health Care Policy and Research’s Evidence Based Report. Otolaryngol Head Neck Surg 2000; 122:1–7. 19. Benninger MS, Applebaum PC, Denneny J, Osguthorpe JD, Stankiewicz J, Zucker D. Maxillary sinus puncture and culture in the diagnosis of acute bacterial rhinosinusitis: the case for pursuing other culture methods. Otolaryngol Head Neck Surg 2002; 127:7–12. 20. Talbot GH, Kennedy DW, Scheld M, Granito K. Rigid nasal endoscopy versus sinus puncture and aspiration for microbiologic documentation of acute bacterial maxillary sinusitis. Clin Infect Dis 2001; 33:1668–1675. 21. Gold S, Tami T. Role of middle meatus aspiration culture in the diagnosis of chronic sinusitis. Laryngoscope 1997; 107(12):1586–1589. 22. Gwaltney JM, Phillips CD, Miller RD, Riker DK. Computed tomographic study of the common cold. N Engl J Med 1994; 330(1):25–30. 23. Benninger MS, Senior B. The development of the rhinosinusitis disability index (RSDI). Arch Otolaryngol Head Neck Surg 1997; 123:1175–1179. 24. Piccirillo J, Merritt J, Richards M. Psychometric and clinimetric validity of the 20-item sino-nasal outcome test. Otolaryngol Head Neck Surg 2002; 126: 41–47. 25. Gliklich R, Hilinski J. Longitudinal sensitivity of generic and speciﬁc health measures in chronic rhinosinusitis. Qual Life Res 1995; 4:27–32.

4 Imaging Sinusitis Nafi Aygun, Ovsev Uzuner, and S. James Zinreich The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Medical Institution, Baltimore, Maryland, U.S.A.

INTRODUCTION Radiological imaging is complementary to the clinical and endoscopic evaluation of patients with rhinosinusitis. The diagnosis of this pathological entity is made clinically and with the help of endoscopy. Imaging is an essential part of presurgical evaluation and monitoring of difﬁcult-to-treat, recurrent, postsurgical disease. In patients in whom there might be clinical suspicion of a noninﬂammatory pathology, imaging can be extremely helpful in distinguishing the various pathological entities.

AVAILABLE IMAGING MODALITIES Plain Sinus Radiograph Plain radiographic evaluation of the paranasal sinuses has fallen out of favor despite its wide availability and comparatively low cost. The overall sensitivity and speciﬁcity of plain radiographs for sinusitis is 40 to 50% and 80 to 90%, respectively (1). The sensitivity approaches clinically acceptable levels only for the diagnosis of maxillary sinus disease (2–4). Generally, for a comprehensive evaluation, four standard views are obtained: lateral view, Caldwell view, Waters’ view, and sub-mentovertex or base view. The lateral view shows the bony perimeter of the frontal, maxillary, and sphenoid sinus (Fig. 1). The Caldwell view shows the bony perimeter of the 55

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Figure 1 Lateral (right) and sub-mentovertical (left) views of the sinuses. Plain radiographs lack the sensitivity, speciﬁcity, and anatomic precision needed for the evaluation of most patients with sinusitis.

frontal sinus. The Waters’ view shows the outlines of the maxillary sinuses, some of anterior ethmoid air cells, and the orbital outline. The sub-mentovertex view evaluates the sphenoid sinus and the anterior and posterior walls of the frontal sinuses (Fig. 1). Evaluation of the ostiomeatal unit (OMU) and the detail of the ethmoid morphology are precluded by this modality. Computerized Tomography Computerized tomography (CT) is the imaging standard for sinusitis (5). Its ability to display bone, mucosa, and air makes it a perfect tool for the imaging of the paranasal sinuses. The ﬁne bony architecture of the nasal cavity and the paranasal sinus drainage pathways is accurately depicted with CT examination. CT is very sensitive in detection of mucosal hypertrophy and retained secretions in the paranasal sinuses. Technique Single channel CT (SC-CT) scanners use either incremental or helical acquisition schemes for paranasal sinus examination. Coronal images optimally display the anterior ostiomeatal unit, the relationship of the orbits and brain to the paranasal sinuses, and also correlate best with the surgical approach. The slice thickness should be 3 mm or less without interslice gap for optimal evaluation of the key structures such as OMU and frontal recess. Image acquisition in the coronal plane requires an extension of the head, which

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may not be possible for very young patients and patients with airway problems or neck pain. Thin axial images can be reconstructed in the coronal plane for such patients. Direct sagittal images cannot be obtained with CT. Multichannel CT (MC-CT) (also called multidetector or multislice CT) scanners have been recently introduced. The single X-ray detector present in SC-CT has been replaced with multiple rows of detectors in MC-CT scanners that allow registration of multiple channels of data with one rotation of the X-ray tube. For example, 16-slice MC-CT equipment has a 16-fold capacity to collect image data per X-ray tube rotation compared to a SC-CT. This increased capacity affords much thinner slices from larger body parts in shorter periods of time. Thin slices permit isotropic data sets in which the voxels (the smallest elements of a data set) are cuboidal. Cuboidal voxels offer excellent reconstruction of images in essentially any plane without degradation of quality. Currently, slices as thin as 0.5 mm can easily be obtained with near-isotropic voxels. Isotropic imaging created a paradigm shift in CT imaging: we are no longer conﬁned to the plane of acquisition. Data can be collected from a body part in any desired plane, and two-dimensional images [multiplanar reconstruction (MPR)] can be displayed in any desired plane (Fig. 2). Real-time interactive manipulation of image data and three-dimensional reconstructions are made possible by high-performance workstations equipped with special software. Intravenous contrast administration is not necessary for assessment of uncomplicated inﬂammatory sinus disease. Different shades of gray inherently present in every CT image can be displayed in various ‘‘windows’’ to enhance visualization of certain tissues (e.g., bones and soft-tissues). A window width of 2000 Hounsﬁeld units with a level of –200 Hounsﬁeld units is the most advantageous for inﬂammatory disease of the paranasal sinuses. These ‘‘window levels’’ afford best display of the narrow air channels. Window settings can easily be changed to highlight certain structures and ‘‘hard-copy’’ ﬁlms are then printed. Adjustment of window settings is not a post-processing method and does not change the raw data, whereas bone reconstruction algorithms (also called bone ﬁlters) manipulate the raw data to best demonstrate the bony detail. Images reconstructed using bone algorithm are recommended for the evaluation of the paranasal sinuses. Evaluation of the soft tissues on these images, however, is very limited, even when the window settings are adjusted for soft tissues (Fig. 3). Radiation Exposure The increasing number of CT examinations and desire for high-resolution images inevitably increase the radiation dose to patients. Factors inherent to the individual CT scanner and the patient greatly inﬂuence radiation dose. Among many operator adjustable scanning parameters that affect the radiation dose, tube current (milliamper-second, mAs) has the most direct and profound effect on the ﬁnal radiation dose received by the

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Figure 2 Paradigm shift in CT imaging: images in virtually any plane can be reconstructed from the acquired data set to better demonstrate a certain structure. (A) Oblique-sagittal reconstruction along the frontal sinus outﬂow tract (arrow). (B) Oblique-coronal reconstruction along the ethmoid infundibulum. (C) Reconstruction along the optic nerve (on) shows dehiscent nerve canal, pneumatized anterior clinoid process (acp) and protrusion of internal carotid artery (ica) to the sphenoid sinus.

patient. A considerable reduction in radiation exposure can be achieved by lowering mAs (6–8). Low mAs results in increased image noise and possible loss of ﬁne detail. A tube current of 50–80 mAs at 120 kVp tube voltage is a reasonable compromise and diagnostic accuracy of paranasal sinus CT is not affected at these settings compared to higher mAs values (9–13). A very low–radiation dose CT (even lower than four view radiographs) study can be performed with 10 mAs and noncontiguous slices for patients who require multiple repeat studies (8). While the radiation exposure to the lens from sinus CT examination is well below the threshold level believed to

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Figure 3 The effect of technical parameters on the appearance of images. (A) Bone window with soft-tissue algorithm, (B) bone window with bone algorithm, (C) softtissue window with soft-tissue algorithm and (D) soft-tissue window with bone algorithm. Note that the bone detail is better depicted on image (B) and soft-tissue is better evaluated on image (C). Patient has CRS and prominent osteitis. Note evidence of prior surgery.

induce cataracts, there is a theoretical risk of stochastic effects (e.g., carcinogenesis), which is not dependent on a minimum threshold of exposure. Therefore, judicious use of CT is advised. Multiple examinations with high-dose protocols should be avoided particularly in young patients. Magnetic Resonance Imaging Magnetic resonance imaging (MRI)’s exquisite contrast resolution makes it a perfect tool in the imaging of soft tissues. MRI is extremely sensitive to

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mucosal thickening. In fact, MRI’s sensitivity may be too high due to the fact that small increases in volume and signal intensity of the mucosa in the ethmoid sinuses and nasal turbinates can be a reﬂection of physiological nasal cycle (14). Due to MRI’s limited ability to display ﬁne bone detail, its use is limited in diagnostic and presurgical evaluation of uncomplicated inﬂammatory sinus disease. MRI has proven most helpful in the evaluation of regional and intracranial complications of inﬂammatory sinus disease and their surgical management, in the detection of neoplastic processes, and in improved display of anatomic relationships between the intra- and extra-orbital compartments. MRI is also useful in the evaluation of mucoceles and cephaloceles. T1- and T2-weighted MRI obtained in axial and coronal planes provide a satisfactory evaluation of the sinuses. Contrast [gadolinium– diethylenetriaminepentaacetic acid (Gd–DTPA)]-enhanced, fat-saturated T1weighted images are recommended for a more comprehensive examination. ANATOMY Understanding of the anatomy of the lateral nasal wall and its relationship to adjacent structures is essential (15–17). The lateral nasal wall contains three bulbous projections: superior, middle, and inferior turbinates (conchae). The turbinates divide the nasal cavity into three distinct air passages: the superior, middle, and inferior meati. The superior meatus drains the posterior ethmoid air cells and, more posteriorly, the sphenoid sinus (through the sphenoethmoidal recess). The middle meatus receives drainage from the frontal sinus [through the frontal sinus outﬂow tract (FSOT)], maxillary sinus (through the maxillary ostium and subsequently the ethmoidal infundibulum), and the anterior ethmoid air cells (through the ethmoid cell ostia). The inferior meatus receives drainage from the nasolacrimal duct. The frontal aeration varies among patients. The frontal sinuses can be small and only occupy the diploic space of the medial frontal bone, or they can be large and extend through the ﬂoor of the entire anterior cranial fossa, posterior to the planum sphenoidale. In general, a central septum separates the left and the right sides. The ﬂoor of the frontal sinus slopes inferiorly toward the midline. The frontal sinus drains through an hourglass-shaped structure. Some call this entity the frontal sinus outﬂow tract (FSOT) (Figs. 2A and 4). The superior portion of this outﬂow tract is a funnel-shaped narrowing called infundibulum in the inferior and medial aspect of the frontal sinus, which leads to the frontal ostium. The frontal ostium forms the waist of the hourglass in the most medial portion of the frontal sinus. The bottom portion of the hourglass is called the frontal recess, the narrowest portion of this outﬂow tract, which in turn leads to the superior portion of the middle meatus affording communication with the anterior ethmoid sinus. The frontal recess is neighbored by the agger nasi cell anteriorly, the ethmoid bulla posteriorly, and uncinate process inferiorly (Fig. 4).

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Figure 4 (A) Axial and (B) oblique sagittal images show the frontal sinus outﬂow tract (arrow) which is mildly narrowed due to circumferential mucosal thickening. Abbreviations: EB, ethmoid bulla; BL, basal lamella; AN, agger nasi cell.

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The agger nasi cell is an ethmoturbinal remnant that is present in nearly all patients. It is aerated and represents the most anterior ethmoid air cell. It usually borders the primary ostium or ﬂoor of the frontal sinus; thus, its size may directly inﬂuence the patency of the frontal recess and the anterior middle meatus. The uncinate process is a superior extension of the lateral nasal wall (medial wall of the maxillary sinus). Anteriorly, the uncinate process fuses with the posteromedial wall of the agger nasi cell and the posteromedial wall of the nasolacrimal duct. Laterally, the free edge of the uncinate process delimits the ethmoid infundibulum, which is the air passage that connects the maxillary sinus ostium to the middle meatus. The superior attachment of the uncinate process has three major variations which determine the anatomic conﬁguration of the frontal recess and its drainage (18). These variations are: (1) the uncinate process may extend laterally to attach to the lamina papyracea or the ethmoid bulla forming a terminal recess of the infundibulum and the frontal recess directly opens to the middle meatus (Fig. 5), (2) the uncinate process may extend medially and attaches to the lateral surface of the middle turbinate, (3) the uncinate process may extend medially and superiorly to directly attach to the skull base (Fig 5). In the latter two forms, the frontal recess drains to the infundibulum. Posterior to the uncinate is the ethmoid bulla (Fig 4b), usually the largest of the anterior ethmoid cells. The ethmoid bulla is enclosed laterally by the lamina papyracea. The gap between the ethmoid bulla and the free edge of the uncinate process deﬁnes the hiatus semilunaris. Medially, the hiatus semilunaris communicates with the middle meatus, the air space lateral to the middle turbinate. Laterally and inferiorly, the hiatus semilunaris communicates with the infundibulum by the air channel between the uncinate process and the inferomedial border of the orbit. The infundibulum serves as the primary drainage pathway from the maxillary sinus. The structure medial to the ethmoid bulla and the uncinate process is the middle turbinate. Anteriorly, it attaches to the medial wall of the agger nasi cell and the superior edge of the uncinate process. Superiorly, the middle turbinate adheres to the cribriform plate. As it extends posteriorly, the middle turbinate emits a number of laterally coursing bony attachments. The ﬁrst of these bony leaﬂets is the basal or ground lamella that fuses with the lamina papyracea posterior to the ethmoid bulla. The basal lamella demarcates the anterior ethmoid sinus from the posterior ethmoid sinus (Fig. 4A). In most individuals, the posterior wall of the ethmoid bulla is intact. The air space between the basal lamella and the ethmoid bulla is the retrobullar recess or the sinus lateralis, which may extend superior to the ethmoid bulla forming the suprabullar recess (Fig. 6). The suprabullar recess opens to the frontal recess. Dehiscence or total absence of the posterior wall of the ethmoid bulla is common and may provide communication between these air spaces.

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Figure 5 Coronal CT. In the most commonly seen anatomic variation, the uncinate process attaches to the lamina papyracea or the ethmoid bulla. The infundibular recess (ir) is formed between the uncinate process and the orbit. In this variation the frontal sinus outﬂow tract drains to the middle-meatus.

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Figure 6 The anatomy of the ethmoid and frontal sinus outﬂow tract on sagittal CT. Abbreviations: AN, agger nasi cell; FR, frontal recess; EB, ethmoid bulla; SR, suprabullar recess; BL, basal lamella.

The posterior ethmoid sinus consists of air cells between the basal lamella and the sphenoid sinus. The number, shape, and size of these air cells vary signiﬁcantly among persons (19–21). The sphenoid sinus is the most posterior sinus (Fig. 7). It is usually embedded in the clivus and bordered superoposteriorly by the sella turcica. Its ostium is located medially in the anterosuperior portion of the anterior sinus wall, which in turn communicates with the sphenoethmoidal recess into the posterior aspect of the superior meatus (Fig. 8). The sphenoethmoidal recess lies just lateral to the nasal septum and can sometimes be seen on coronal images, but it is best seen in the sagittal and axial planes. The relationship between the aerated portion of the sphenoid sinus and the posterior ethmoid sinus needs to be accurately represented so the surgeon can avoid operative complications. Usually in the paramedian sagittal plane, the sphenoid sinus is the most superior and posterior air space. More laterally, the sphenoid sinus is located more inferiorly, and the posterior ethmoid air cells become the most superior and posterior air space. This relationship is seen well on transverse and sagittal images. The number and position of the septa of the sphenoid sinus vary. Some septa can adhere to the bony wall covering the internal carotid artery, which frequently penetrates the sphenoid sinus. Note is to be made that all septations are vertically oriented within the sphenoid sinus. Horizontal bony separations within the area of the sphenoid sinus represent a bony separation between the posterior ethmoid sinus cells above and the sphenoid sinus below.

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Figure 7 The sphenoid sinus and carotid artery. Contrast-enhanced (A) coronal and (B) sagittal images show protrusion of internal carotid artery (ica) into the sphenoid sinus with dehiscent carotid canal. Note that on a noncontrast CT displayed with bone windows this would be indistinguishable from a sphenoid polyp. Arrows: ICA.

Anatomically, the paranasal sinuses are in close proximity to the anterior cranial fossa, cribriform plate, internal carotid arteries, cavernous sinuses, the orbits and their contents, and the optic nerves as they exit the orbits (Figs. 2C and 7) (22–24). The surgeon should be cautious when

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Figure 8 Axial CT image through the sphenoid sinus. The sphenoid ostium is at the medial and superior aspect of the sphenoid sinus. Note that the left ostium is obstructed by mucosal thickening.

maneuvering instruments in the posterior direction to avoid an inadvertent penetration and drainage of these structures (22,23,25,26). Anatomic Variations and Congenital Abnormalities The nasal anatomy is unique and similar to the uniqueness of ‘‘thumb print.’’ Although the nasal anatomy varies signiﬁcantly among patients, certain anatomic variations are common in the general population and may be seen more frequently in patients with chronic inﬂammatory disease (20,21,25–28). Multiple studies demonstrated an association between some anatomic variations and sinusitis, but a causal relationship has not been established. It appears that some of these variations contribute to mechanical obstruction of the ostiomeatal channels in patients with sinusitis, and need to be addressed during surgery. The signiﬁcance of an anatomic variation is determined by its relationship with the ostiomeatal channels and nasal air passages. The most common variations are discussed in the following paragraphs. It is stressed that the high variability of the anatomy necessitates careful presurgical assessment on an individual basis. Concha Bullosa Concha bullosa is deﬁned as an aeration of the middle turbinate (Fig. 9). Concha bullosa may be unilateral or bilateral. Less frequently, aeration of

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Figure 9 Concha Bullosa: coronal CT image showing bilateral concha bullosa. The right concha bullosa is opaciﬁed.

the superior turbinate may occur, whereas aeration of the inferior turbinate is infrequent. A concha bullosa in the middle turbinate may enlarge to obstruct the middle meatus or the infundibulum. The air cavity in a concha bullosa is lined with the same epithelium as the rest of the nasal cavity; thus, these cells can undergo the same inﬂammatory disorders experienced in the paranasal sinuses. Obstruction of the drainage of a concha can lead to mucocele formation. Nasal Septal Deviation Nasal septal deviation is an asymmetric bowing of the nasal septum that may compress the middle turbinate laterally, narrowing the middle meatus. Bony spurs are often associated with septal deviation. Nasal septal deviation is usually congenital but may be a post traumatic ﬁnding in some patients. Nasal septal deviation occurs with a similar frequency in asymptomatic persons with no CT evidence of sinusitis and in patients with sinusitis (29). When the angle of deviation is high, it may contribute to the mechanical obstruction of the anterior ostiomeatal complex.

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Paradoxic Middle Turbinate The middle turbinate usually curves medially towards the nasal septum. However, its major curvature can project laterally and, thus, narrow the middle meatus and infundibulum. This variant is called a paradoxic middle turbinate. The inferior edge of the middle meatus may assume various shapes with excessive curvature, which in turn may obstruct the nasal cavity, infundibulum, and middle meatus. Variations in the Uncinate Process The course of the free edge of the uncinate process varies. In most cases, it extends slightly obliquely toward the nasal septum with the free edge surrounding the inferior or anterior surface of the ethmoid bulla. Sometimes, the free edge of the uncinate adheres to the orbital ﬂoor or inferior/anterior aspect of the lamina papyracea. This variant is usually associated with a hypoplastic (Fig. 10), and often opaciﬁed, ipsilateral maxillary sinus resulting from closure of the infundibulum. Due to the small maxillary sinus, the

Figure 10 Hypoplastic maxillary sinus: the uncinate is attached to the ﬂoor of the orbit on this coronal CT image. Also note that the wall of the maxillary sinus is very thick.

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ipsilateral orbit is more inferiorly located, giving rise to more frequent orbital complications during surgery (30,31). The posterior edge of the uncinate process may attach to the lamina papyracea, wall of the ethmoid bulla, middle turbinate, or skull base. The attachment site of the posterior edge of the uncinate process determines the drainage site of the frontal recess. Haller Cells (Infrabullar Recess Cells) Haller cells are ethmoid air cells that extend along the medial roof of the maxillary sinus (Fig. 11). Their appearance and size vary. They may cause narrowing of the infundibulum when they are large. Haller cells may exist as discrete cells or they may open into the maxillary sinus or infundibulum. Onodi Cells Onodi cells are lateral and posterior extensions of the posterior ethmoid air cells (32). They extend the paranasal sinus cavity very near the optic nerves

Figure 11 Haller cell: bilateral extension of ethmoid cells into the maxillary sinuses. Note the proximity of the Haller cells to the ethmoid infundibulum.

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as they exit the orbits. These cells may surround the optic nerve tract and put the nerve at risk during surgery. Giant Ethmoid Bulla The largest of the ethmoid air cells, the ethmoid bulla may enlarge to narrow or obstruct the middle meatus and infundibulum. Extensive Pneumatization of the Sphenoid Sinus Pneumatization of the sphenoid sinus can extend into the anterior clinoid processes and clivus, surrounding the optic nerves. When this occurs, the risk of damage to the optic nerves is increased during surgical exploration. The carotid canal may protrude into the sphenoid sinus and there could be a bony dehiscence on the sphenoid sinus wall, increasing the risk of catastrophic carotid artery injury. Medial Deviation or Dehiscence of the Lamina Papyracea Medial deviation or dehiscence of the lamina papyracea may be a congenital ﬁnding or the result of prior facial trauma. Regardless, the intra-orbital contents are at risk during surgery because of the common dehiscences in the area and the ease of confusing this medial bulge with the ethmoid bulla. Excessive medial deviation and bony dehiscence tend to occur most often at the site of the insertion of the basal lamella into the lamina papyracea, thus rendering this portion of the lamina papyracea most delicate. Aerated Crista Galli Aeration of the crista galli, a normally bony structure, can occur (Fig. 12). When aerated, these cells may communicate with the frontal recess. Obstruction of this ostium can lead to chronic sinusitis and mucocele formation. It is important to recognize this entity preoperatively and to differentiate it from an ethmoid air cell to avoid extension of surgery into the cranial vault. Cephalocele and Meningocele Extracranial herniations of the brain and/or its coverings may be congenitally present or may result from previous ethmoid or sphenoid sinus surgery. Their presence needs to be considered when dealing with an isolated softtissue mass adjacent to the ethmoid or sphenoid roof, especially if complemented by adjacent bone erosion. The differential diagnosis includes mucocele, neoplasm, cephalocele, and less likely, a polyp associated with an adjacent bony dehiscence. Coronal CT will best display the extent of bony erosion, and sagittal and coronal MRI will be helpful in narrowing the differential diagnosis. CT cisternography is diagnostic (Fig. 13).

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Figure 12 Supraorbital ethmoid air cells and pneumatized crista galli demonstrated on coronal CT image.

Asymmetry in Ethmoid Roof Height It is important to note any asymmetry in the height of the ethmoid roof (Fig. 14). The incidence of intracranial penetration during functional endoscopic sinus surgery (FESS) is higher when this anatomic variation occurs. Intracranial penetration is more likely to occur on the side where the position of the roof is lower (23). Acquired abnormalities of the sinus walls such as osteoma and ﬁbrous dysplasia are relatively common and usually asymptomatic. They can present with sinus-related complaints when they interfere with sinus drainage. IMAGING RHINOSINUSITIS Acute Rhinosinusitis Air–ﬂuid levels and complete opaciﬁcation of a sinus are the imaging hallmarks of acute rhinosinusitis (ARS) (Fig. 15). More than one sinus are usually involved, typically the maxillary and the ethmoid sinuses. CT is much more sensitive than plain radiographs. Air–ﬂuid level is a very

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Figure 13 Cephalocele: CT-cisternogram in the coronal plane demonstrates CSF containing sacs in the pterygoid recesses of the sphenoid sinus.

Figure 14 Low fovea ethmoidalis: the left cribriform plate is more inferiorly positioned than the right.

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Figure 15 Characteristic CT appearance of acute sinusitis on axial contrastenhanced image: low attenuation ﬂuid retention in the sphenoid and ethmoid sinuses with air ﬂuid levels. Also note that the patient has left preseptal cellulitis.

speciﬁc sign for ARS in the appropriate clinical setting. Other causes of altered air–ﬂuid level in a sinus include trauma, prolonged supine position, and intubation (typical ICU patient), recent nasal irrigation, cerebrospinal ﬂuid (CSF) leak, and chronic rhinosinusitis (CRS). ARS is diagnosed on the basis of history, clinical presentation, and physical examination. Imaging is not recommended for diagnosing ARS because of the cost-containment concerns and radiation exposure, unless the patient is not responding to initial treatment or there is a complicating factor (33–35). A limited sinus CT consisting of ﬁve to six axial noncontiguous images is utilized in many practices for the initial diagnosis of ARS. The charge for limited sinus CT is only slightly higher than the charge for plain radiographs and the radiation dose is reduced, while the diagnostic accuracy remains reasonably high. The cost-effectiveness of limited sinus CT exam, which changes with evolving technology and its impact on treatment plan, has not been well studied (36). When the clinical question is whether there is sinusitis or not, a limited sinus CT would be adequate. The reduced cost and radiation dose of limited sinus CT cannot be used as a justiﬁcation for imaging of uncomplicated ARS. Authors believe that the diagnosis of ARS should be made clinically, and that when imaging is necessary, a ‘‘high quality’’ CT exam should be performed. ARS is often a self-limited disease and symptoms subside with or even without treatment; however, in rare instances, catastrophic complications

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Figure 16 Sub-periosteal abscess: contrast-enhanced coronal CT shows acute sinusitis of the left maxillary and ethmoid with a peripherally enhancing ﬂuid attenuation mass in the left extraconal orbit.

occur. Because of the close proximity of the sinuses to the brain and orbit, and the naturally present dehiscences and vascular channels in the sinus walls, infection can spread to the orbit and intracranial compartment. Sub-periosteal phlegmon and abscess result when the infection is limited by the intact periorbita (Fig. 16). Penetration of the periorbita allows infection to spread to the orbital soft tissues causing orbital cellulitis, which may lead to permanent loss of vision. Intracranial complications such as meningitis, epidural and subdural empyema, brain abscess, and cavernous sinus thrombophlebitis typically occur in the setting of frontal and sphenoid sinusitis (Fig. 17). Early identiﬁcation and treatment are essential in preventing catastrophic results. Contrast-enhanced CT detects most orbital complications. MRI is the study of choice for intracranial extension. Subacute Rhinosinusitis Subacute rhinosinusitis is clinically deﬁned as persistence of symptoms for more than four weeks and up to 12 weeks. There is no speciﬁc radiological sign for subacute rhinosinusitis and a typical CT study shows some opaciﬁcation of one or more sinuses. Chronic Rhinosinusitis The term chronic rhinosinusitis (CRS) is preferred because rhinitis almost always precedes sinusitis and sinusitis occurs concurrently with inﬂammation

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Figure 17 Subdural empyema: axial (A) T2-weighted and (B) post-contrast T1-weighted MRI show subdural collections on this patient who was diagnosed with acute frontal sinusitis one week prior to this MRI.

of the nasal passages (37,38). CRS diagnosis is symptom-based and requires persistence of patient complaints for more than 12 consecutive weeks. Since many clinical symptoms of CRS are vague, subjective, and nonspeciﬁc, objective demonstration of mucosal inﬂammation is necessary to conﬁrm the clinical diagnosis (37,39–41). Anterior rhinoscopy may not always be able to conﬁrm the presence of mucosal inﬂammation, and nasal endoscopy is required to visualize the middle meatus and ethmoid bulla (41). CT, as the imaging standard for evaluation of the sinuses, is an excellent tool to conﬁrm the presence and assess the extent of inﬂammation in the sinonasal cavity beyond what is permitted by endoscopy (5,42). The plain radiographs lack the sensitivity, speciﬁcity, and anatomic precision needed for the management of these patients and are simply inadequate. Limited sinus CT examinations which employ selected, noncontiguous axial slices may be adequate in some clinical scenarios when the patient had a thorough evaluation of the anatomy with a high quality CT previously. One has to keep in mind, though, that the limited sinus study is limited not only in cost and radiation exposure, but in information as well. Although CT provides excellent information about the extent and distribution of mucosal disease and status of the nasal air passages, it does not yield much information about the origin of the changes (e.g., infection, allergies, granulomatous inﬂammation, postsurgical scarring, etc.). The CT signs suggestive of CRS include diffuse or focal mucosal thickening, partial or complete opaciﬁcation, and bone remodeling and thickening caused by osteitis from adjacent chronic mucosal inﬂammation and polyposis (Fig. 18). The distribution of the inﬂammatory mucosal changes

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Figure 18 Diffuse nonspeciﬁc CRS: bilateral ethmoid and maxillary opaciﬁcation. Note prior uncinectomy, middle turbinectomy, and ethmoidectomy.

in the nasal cavity and sinuses may provide a clue as to the level of mechanical obstruction. Babble et al. (43) deﬁned ﬁve recurring patterns of inﬂammatory sinonasal disease including infundibular, OMU, sphenoethmoidal recess, sinonasal polyposis, and sporadic or unclassiﬁable disease. In this study, the infundibular pattern (26% of patients) referred to the focal obstruction within the maxillary sinus ostium and ethmoid infundibulum that was associated with maxillary sinus disease. The OMU pattern (25% of patients) referred to ipsilateral maxillary, frontal, and anterior ethmoid sinus disease. This pattern was caused by obstruction of the middle meatus. The frontal sinus is sometimes spared because of the variability in frontal sinus drainage pathway. The sphenoethmoidal recess pattern (6% of patients) resulted in sphenoid or posterior ethmoid sinus inﬂammation caused by sphenoethmoidal recess obstruction. Diffuse nasal and paranasal sinus polyps occurred in 10% of the study population (sinonasal polyposis pattern). One-fourth of the patients in this study did not show a recognizable pattern. Zinreich and others found middle-meatus opaciﬁcation in 72% of patients with chronic sinusitis; 65% of these patients had mucosal thickening

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of the maxillary sinus (20,21,26). The patients with frontal sinus inﬂammatory disease had opaciﬁcation of the frontal recess (20,21,26). Frontal sinus opaciﬁcation involving the OMU without maxillary or anterior ethmoid sinus inﬂammatory disease was rare (20,21,26). Yousem et al. (44) found that when the middle meatus was opaciﬁed, associated inﬂammatory changes occurred in the ethmoid sinuses in 82% of patients and in the maxillary sinuses in 84%. Bolger et al. (45) found that when the ethmoid infundibulum was free of disease, the maxillary and frontal sinuses were clear in 77% of patients. Certain anatomic variants, as described, have been implicated as causative factors in the presence of chronic inﬂammatory disease. Lidov and Som (46) found that a large concha bullosa could produce signs and symptoms by narrowing the infundibulum. However, Yousem et al. (44) found that the presence of a concha bullosa did not increase the risk of sinusitis. This was corroborated by Bolger et al. (45) who found that concha bullosa, paradoxic turbinates, Haller cells, and uncinate pneumatization were not signiﬁcantly more common in patients with chronic sinusitis than in asymptomatic patients. Yousem et al. (44) found that nasal septal deviation and a horizontally oriented uncinate process were more common in patients with inﬂammatory sinusitis. Although these variants may not necessarily predispose to sinusitis, the size of a given anatomic variant and its relationship to adjacent structures are important in the development of sinusitis (19). When sinus secretions are acute and of low viscosity, they are of intermediate attenuation on CT (10–25 Hounsﬁeld units). In the more chronic state, sinus secretions become thickened and concentrated, and the CT attenuation increases with density measurements of 30 to 60 Hounsﬁeld units (Fig. 19) (47). Sinonasal polyposis has been recognized as a distinct form of CRS, both clinically and radiographically, although polyp formation is a nonspeciﬁc response to variety of inﬂammatory stimuli (Fig. 20). There is an obvious association with asthma, aspirin-sensitivity, and eosinophilia. The pathogenesis of sinonasal polyposis is very complex and not clearly understood (48–50). However, high recurrence rate of sinonasal polyposis is well documented (51–54). Antrochoanal and sphenochoanal polyps appear as well-deﬁned masses that arise from the maxillary or sphenoid sinus and extend to the choana through the middle meatus or sphenoethmoid recess, respectively (Fig. 21). They can present as nasopharyngeal masses. It is important to recognize their origin and relation to the maxillary or sphenoid ostium in treatment planning. Retention cysts are very common incidental ﬁndings in imaging studies and seen as very well-deﬁned rounded masses, typically in the maxillary sinus ﬂoor (Fig. 22). Their clinical signiﬁcance is not clear (55). They may become symptomatic if large enough to interfere with drainage pathways (56). Mucoceles, a complication of CRS, result from the obstruction of the sinus drainage and subsequent expansion of the sinus (Fig. 23). Mucoceles

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Figure 19 Right-sided ethmoid and maxillary sinusitis with obstruction of the ostiomeatal unit is demonstrated on this coronal CT image. The central high attenuation in the maxillary sinus suggests chronic secretions with high protein content.

are more commonly seen in the ethmoid and frontal sinuses and present with symptoms secondary to compression of the adjacent structures in addition to usual symptoms of CRS. Thickening and sclerosis of the bony walls of the sinuses (Fig. 24) have been traditionally attributed to the secondary reaction of the bone to a chronic mucosal inﬂammation. More recent work suggests that the bone may actually play an active part in the disease process and that the inﬂammation associated with CRS may spread through the haversian system within the bone (57,58). The combination of a surgical procedure and experimentally induced sinusitis creates an inﬂammatory process within bone with the classic histological features of osteomyelitis. Furthermore, bone inﬂammation may induce chronic inﬂammatory changes in the overlying mucosa at a signiﬁcant distance from the site of infection. Identiﬁcation of bone thickening and sclerosis on CT exam is straightforward, due to CT’s exquisite ability to show the bone detail.

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Figure 20 Typical CT appearance of sinonasal polyposis in the coronal plane.

On MRI, the appearance of CRS varies because of the changing concentrations of protein and free water protons (59). Som and Curtin (47) describe four patterns of MRI signal intensity that can be seen with chronic sinusitis: (1) hypointense on T1-weighted images and hyperintense on T2-weighted images with a protein concentration less than 9%; (2)

Figure 21 Antrochoanal polyp: coronal CT images show a nasopharyngeal mass that can be followed to the expanded maxillary ostium. The right maxillary sinus and nasal fossa are opaciﬁed.

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Figure 22 Typical appearance of a retention cyst.

Figure 23 Frontal mucocele. Coronal CT image shows expansion of the left frontal sinus into the orbit with marked thinning of the sinus wall.

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Figure 24 CRS and osteitis: marked thickening of the sinus walls.

hyperintense on T1-weighted images and hyperintense on T2-weighted images with total protein concentration increased by 20% to 25%; (3) hyperintense on T1-weighted images and hypointense on T2-weighted images with total protein concentration of 25% to 30%; and (4) hypointense on T1weighted images and T2-weighted images with a protein concentration greater than 30% and inspissated secretions in an almost solid form. MRI of inspissated secretions (i.e., those with protein concentrations greater than 30%) may have a pitfall in that the signal voids on T1- and T2-weighted images may look identical to normally aerated sinuses. The correlation between patient symptoms and CT ﬁndings is difﬁcult to determine partly due to the fact that chronic mucosal inﬂammation may be present without the ﬁndings identiﬁed on CT examinations such as mucosal hypertrophy and retained secretions and that a modest amount of inﬂammation diagnosed by CT may be present in asymptomatic persons. Several studies failed to show a correlation between symptom severity and severity of CT ﬁndings (40,41,60–62). Particularly, symptoms such as headache and facial pain do not correlate with CT ﬁndings at all (63–65). A positive correlation between the severity of symptoms and CT ﬁndings may be demonstrated when certain symptoms and negative CT exams are eliminated (66,67). The nasal endoscopy ﬁndings correlate with CT ﬁndings, though the correlation is less than perfect (41,63,68). The positive predictive value of abnormal endoscopy for abnormal CT is greater than 90%, whereas the negative predictive value of normal endoscopy for normal CT is only 70% (41,63).

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To better classify patients into diagnostic and prognostic categories, various symptom-, CT-, and endoscopy- scoring systems have been used. The Lund–MacKay scoring system is the most popular method applied to CT description of sinus disease because of its simplicity and reproducibility (69). A score of 0, 1, or 2 is given to each of the ﬁve sites (anterior ethmoid, posterior ethmoid, frontal, maxillary, and sphenoid) on both sides of the sinonasal cavity for normal pneumatization, partial opaciﬁcation, or complete opaciﬁcation, respectively (70,71). The ostiomeatal complex receives either 0 or 2. This yields a maximum score of 12 for one side. In a small study, the impact of CT on treatment decision was evaluated (36). CT changed the treatment in one-third of the patients and provided better agreement on treatment plan among ENT surgeons (36). Fungal Rhinosinusitis Fungal rhinosinusitis (FRS) differs from bacterial and other types of sinusitis not only in etiology but also in demographics of the effected population, clinical approach, diagnosis, treatment, and prognosis. There are two main forms of FRS: invasive and noninvasive (72). Within these categories, ﬁve clinicopathologically distinct entities are deﬁned (73): (i) acute invasive, (ii) chronic invasive granulomatous form, (iii) chronic invasive nongranulomatous form, (iv) fungus ball and (v) allergic fungal sinusitis. It must be emphasized that FRS is a spectrum of disease and the differences in clinical presentation are largely determined by the host defense system. Therefore, it is not uncommon to see overlapping clinical and imaging features. Acute Invasive FRS Acute invasive FRS is seen primarily in immunocompromised patients and is fatal if untreated. A high index of clinical suspicion and biopsy of the middle turbinate are necessary for early diagnosis, which may be life-saving (74). CT study obtained early in the disease course may be normal or show nonspeciﬁc mucosal thickening indistinguishable from the appearance of bacterial/ viral disease (75) (Fig. 25). Bone destruction and swelling of the soft tissues adjacent to the paranasal sinuses occur in advanced disease. Chronic Invasive FRS Chronic invasive FRS has been associated primarily with immunocompromised patients; however, it does occur in the non-immunocompromised as well and has a more protracted course with relatively slow progression of disease, sometimes despite treatment, and high recurrence rate. There is no apparent difference in clinical and radiological features of the granulomatous and nongranulomatous forms. The radiological hallmark of chronic invasive FRS is bone destruction, which is better depicted with CT, whereas MRI better deﬁnes the soft-tissue extent of disease and brain involvement.

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Figure 25 Acute invasive fungal sinusitis. On this patient with advanced leukemia and prior sinus surgery, axial CT shows nonspeciﬁc mucosal thickening in the ethmoid cells. Biopsy proven acute invasive sinusitis.

Foci of increased attenuation (on CT) in the sinus mucosal thickening may indicate fungal colonization as found in 74% of our patient population (76). The radiological differential diagnosis of chronic invasive FRS is broad and includes benign and malignant neoplasms, infectious and idiopathic granulomatous diseases, and allergic fungal sinusitis. Fungus Ball Fungus ball refers to a sinus mass that consists of packed hyphae. Patients with fungus ball are typically immunocompetent and present with varying nonspeciﬁc sinus-related complaints. Serendipitous identiﬁcation of fungus balls is not uncommon. Diffuse opaciﬁcation of a single sinus is the most common radiographic feature (77). Foci of hyperattenuation in the center of the sinus mass is seen in approximately 50 to 74% of the patients (75,77,78). Large calciﬁed concretions are characteristic of the disease but uncommonly found (Fig. 26). Thickening of the sinus walls is common. Bone erosion may occasionally be seen. Allergic FRS Allergic FRS, an immunologically mediated hypersensitivity reaction to fungi, is the most common fungal disease of the sinuses (79). A central area of hyperattenuation on sinus CT is almost always present and corresponds to markedly decreased T2 signal on MRI. This appearance is due to the metabolized ferromagnetic elements (primarily iron) and calcium within the concretion (Fig. 27). Expansion of the involved sinuses with bone remodeling or destruction is common.

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Figure 26 Fungus ball: dense calciﬁcation in the center of the completely opaciﬁed left maxillary sinus is shown on this coronal CT image.

Saprophytic Colonization Saprophytic colonization of the sinonasal mucosa is very common, particularly in patients who had undergone sinus surgery, and mere presence of fungi on the mucosa does not necessarily constitute the disease.

PRESURGICAL IMAGING EVALUATION Using a systematic approach is helpful when interpreting sinus CT studies. One must identify and describe the important structures of the paranasal sinuses including the frontal sinus, the FSOT, the agger nasi cell and anterior ethmoid sinus, the ethmoid roof, the ethmoid bulla, the uncinate process, the infundibulum, the maxillary sinus, the middle meatus, the nasal septum and nasal turbinates, the basal lamella, the sinus lateralis, the posterior ethmoid sinus, the sphenoid sinus, and the sphenoethmoidal recess. The symmetry of the ethmoid roof should be noted. If not recognized, discrepant heights of the ethmoid roof may lead to inadvertent penetration of the cranial vault during surgery (23).

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Figure 27 Allergic fungal sinusitis (AFS): axial (A) and coronal (B) CT, axial T2-weighted and post-contrast coronal T1-weighted MRI. Predominantly high attenuation, heterogeneous mass in the right-sided sinuses with erosion into the orbit, the middle, and posterior cranial fossae. Note that the mass in the sphenoid and parts of the ethmoid sinuses shows essentially no signal on T2-weighted MRI.

Careful attention should be paid to the status of the lamina papyracea, and any dehiscence or excessive medial deviation of this bone should be reported. The relationship of the sphenoid sinus and posterior ethmoid air cells with the internal carotid artery and optic nerves should be noted. In particular, extensive expansion of the sinuses around the internal carotid artery or the optic nerve and bony dehiscences adjacent to either structure should be noted. The incidence of bony dehiscence around the parasellar

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portions of the internal carotid artery is 12% to 22% (80). The carotid canal frequently penetrates the aerated portion of the sphenoid sinus; in many cases, the sphenoid sinus septa will adhere to the bony covering of the carotid canal. The surgeon needs to be aware of this variation to prevent fracture of the sphenoid sinus septum–carotid canal junction and avoid puncturing the carotid canal. Cephaloceles can be present in the sphenoid and ethmoid sinuses and mimic inﬂammatory disease. Any bony dehiscence should be evaluated with the possibility of encephalocele in mind. The relationship between the posterior paranasal sinuses and the optic nerves is important to note to avoid operative complications (Fig. 28). Delano et al. (81) classiﬁed this relationship into four categories depending on the relationship of optic canal and sphenoid and posterior ethmoid sinuses. In this study, the optic nerve canal was dehiscent in all cases in which it traveled through the sphenoid sinus (type 3), in 82% of cases in which the nerve impressed on the sphenoid sinus wall (type 2), and in 77% of cases in which the anterior clinoid process is pneumatized. The presence of anterior clinoid process pneumatization is an important indicator of optic nerve vulnerability during FESS because of frequent associations with bony dehiscence and type 2 and 3 conﬁgurations. Hypoplastic maxillary sinus is usually accompanied by variations in the lateral nasal wall anatomy and orbital ﬂoor, which may give rise to surgical complications, if not recognized (30,31). The bony outline of the nasal cavity and paranasal sinuses must be examined with particular attention to absence of bone. Surgical removal of bone should be documented. Bone erosion or destruction may be secondary

Figure 28 Contrast-enhanced coronal CT image of the sphenoid sinus: aerated anterior clinoid processes with bulging of the optic nerves into the sphenoid sinus.

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to mucocele or neoplasm; the associated mAss and pattern of bone involvement are helpful clues as to the cause, and MRI may distinguish between these processes. POSTSURGICAL IMAGING EVALUATION The presence or absence of important structures should be identiﬁed and mentioned. The nasal cavity and paranasal sinus boundaries and important anatomical relationships should be inspected. Areas of bony thickening or dehiscence should be noted. The following merit close scrutiny on follow-up CT scan: The frontal recesses should be identiﬁed to determine their patency. Postoperatively, recurrence of disease is caused by persistent obstruction in this area, which is the narrowest channel within the anterior ethmoid complex and is difﬁcult to access surgically. Therefore, the frontal recess is most likely to be affected with inﬂammatory disease in a patient who underwent previous surgery in the paranasal sinuses. The agger nasi cell (if it remains) should be noted because of its persistence may continue to narrow the frontal recess. In patients who had partial middle turbinate resection, one should look for lateralization of the remnant middle turbinate which may be the cause of obstruction of the frontal recess, middle meatus, and/or infundibulum. The extent of the excision of the uncinate and removal of the ethmoid bulla should be noted. The course of the infundibulum should be examined for persistent anatomic narrowing. Careful attention should be paid to the vertical attachment of the middle turbinate to the cribriform plate and to the attachment of the basal lamella to the lamina papyracea. Traction on the vertical attachment and basal lamella of the middle turbinate during the course of middle turbinectomy can fracture the lamina papyracea or the cribriform plate. The course of the lamina papyracea should be inspected to evaluate the integrity of this structure. Postoperative dehiscences are commonly found posterior to the nasolacrimal duct and may be caused by the uncinate resection. Asymmetry in position of the roof of the ethmoid sinus should be noted. Intracranial penetrations are usually on the side where the position of the roof is lower. SURGICAL COMPLICATIONS In general, complications can be divided into minor and major (22,23,82). Minor complications include periorbital emphysema, epistaxis, postoperative

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nasal synechiae, and tooth pain. Although these can commonly occur, they are usually self-limited and do not require postoperative radiological evaluation. Major complications are rare but can be severely devastating or fatal (22). A preexisting loss of integrity of the lamina papyracea can permit intraorbital fat to herniate into the ethmoid sinuses. Preexisting dehiscence of the lamina papyracea may be caused by prior trauma or erosion from chronic sinus disease. Disruption of the lamina papyracea can occur during resection of the middle turbinate if the basal lamella is resected back to its attachment to the lamina papyracea. The medial rectus muscle, superior oblique muscle, or other orbital contents can be directly damaged if preexisting or intraoperative disruption of the lamina papyracea occurs (83). If intra-orbital and intraocular pressure builds up as a result of an expanding hematoma or air being forced into the orbit from the nasal cavity (through a dehiscent lamina papyracea), then visual impairment or blindness secondary to ischemia can result (83). Temporary or permanent blindness caused by injury of the optic nerve can occur during posterior ethmoidectomy if the bony limit of the sinus is violated (22,23,82,83). Trauma to the vessels supplying the optic nerve also can result in visual loss. Perforation of the cribriform plate can lead to intracranial hematoma, infection, and cerebrospinal ﬂuid (CSF) leak. Massive hemorrhage from direct injury to major vessels can occur. Laceration of the internal carotid artery has been reported and is often fatal (22,23). Emergent angiography and balloon occlusion of the lacerated artery have been performed. Patients who report severe postoperative headache or photophobia or who have signs that suggest subarachnoid hemorrhage should undergo noncontrast head CT. If subarachnoid blood is found, cerebral angiography is recommended to detect vascular injury. Injury to the nasolacrimal duct can result during anterior enlargement of the maxillary ostium in the middle meatus. Injury to the membranous portion of the duct may be self-limited and remit by spontaneous ﬁstulization into the middle meatus. Stenosis or total occlusion of the nasolacrimal duct can result from more severe injury (83). Postoperative CSF leak due to inadvertent penetration of the dura is another major complication of FESS. A CSF leak may not become clinically apparent for up to two years after surgery (23). CSF leaks will often close spontaneously with conservative measures (e.g., lumbar drain). However, if they persist, radiological workup is indicated. In many institutions, a radionuclide CSF study is the initial radiological screening examination in such patients. Three to four absorbent pledgets are placed on each side of the nasal cavity and 400 to 500 mCi of indium-111 (111-In)-labeled DTPA is instilled into the subarachnoid space through a cervical or lumbar puncture. Then, the patient undergoes imaging with a gamma camera at multiple intervals for

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up to 24 hours. Any position or activity known to provoke the leak is encouraged. Although images of the head and neck are obtained, evidence of the leak is unusual on these images. Rather, indirect signs of leaking are sought. Images over the abdomen are done to search for activity in the bowel, which indicates that the patient is swallowing CSF as it leaks into the nasal cavity. At 24 hours, the nasal pledgets are removed and assayed. The results are compared with 111-In activity in a serum sample drawn at the same time. A ratio of pledget activity to serum activity is determined. It is then possible to predict the general area of the leak based on which pledgets show increased activity. If none of the pledgets have increased activity but activity over the abdomen is increased, the radionuclide test is considered positive. When the radionuclide test is positive (directly or indirectly), a contrast CT-cisternogram, which involves intrathecal administration of 3–5 ml of water-soluble contrast media and coronal CT scanning, is done to deﬁne the anatomy and pinpoint the site of leakage. COMPUTER-AIDED SURGERY Computer-aided surgery (CAS) is being increasingly utilized in FESS (84). CAS offers many advantages including real-time correlation of CT images, surgical ﬁeld, and position of the surgical devices. Delicate anatomic dissection, yielding more complete surgeries in difﬁcult places and fewer complications, is afforded by CAS. Several CAS systems such as SAVANT (CBYON, Palo Alto, CA), InstaTrak (Visualization Technology, Woburn, MA), LandMarX (Medtronic Xomed, Jacksonville, FL), and VectorVision (BrainLab, Tottlingen, Germany) are in use, and they allow projection of the location of surgical instruments in the operative ﬁeld on the CT image data set. The most important components of a CAS system include registration and tracking units. Registration involves mapping of certain points in the preoperative image data set to the corresponding points in the operative ﬁeld. To accomplish this, certain anatomic landmarks, special headsets, or radiopaque ﬁducial markers placed on the patient’s skull can be used. Tracking systems, using electromagnetic or optical sensors, monitor the ever-changing position of surgical instruments. The position of instruments is displayed on the image data. The navigational accuracy is dependent on the accuracy of registration, tracking, and also the quality of CT image data set. Through technological advancements, a high level of accuracy (usually within 1 mm) has been achieved (85–91). An inherent limitation of CAS is that the surgically created changes are not reﬂected on CT images since there is no intraoperative image acquisition. REFERENCES 1. Engels EA, Terrin N, Barza M, Lau J. Meta-analysis of diagnostic tests for acute sinusitis. J Clin Epidemiol 2000; 53:852–862.

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18. Daniels DL, Mafee MF, Smith MM, Smith TL, Naidich TP, Brown WD, Bolger WE, Mark LP, Ulmer JL, Hacein-Bey L, Strottmann JM. The frontal sinus drainage pathway and related structures. Am J Neuroradiol 2003; 24: 1618–1627. 19. Yousem DM. Imaging of sinonasal inﬂammatory disease. Radiology 1993; 188:303–314. 20. Zinreich SJ. Imaging of chronic sinusitis in adults: X-ray, computed tomography, and magnetic resonance imaging. J Allergy Clin Immunol 1992; 90: 445–451. 21. Zinreich SJ. Paranasal sinus imaging. Otolaryngol Head Neck Surg 1990; 103:863–868; discussion 868–869. 22. Maniglia AJ. Fatal and other major complications of endoscopic sinus surgery. Laryngoscope 1991; 101:349–354. 23. Hudgins PA, Browning DG, Gallups J, Gussack GS, Peterman SB, Davis PC, Silverstein Am, Beckett WW, Hoffman JC Jr. Endoscopic paranasal sinus surgery: radiographic evaluation of severe complications. Am J Neuroradiol 1992; 13:1161–1167. 24. Buus DR, Tse DT, Farris BK. Ophthalmic complications of sinus surgery. Ophthalmology 1990; 97:612–619. 25. Zinreich J. Imaging of inﬂammatory sinus disease. Otolaryngol Clin North Am 1993; 26:535–547. 26. Zinreich SJ, Kennedy DW, Rosenbaum AE, Gayler BW, Kumar AJ, Stammberger H. Paranasal sinuses: CT imaging requirements for endoscopic surgery. Radiology 1987; 163:769–775. 27. Jones NS, Strobl A, Holland I. A study of the CT ﬁndings in 100 patients with rhinosinusitis and 100 controls. Clin Otolaryngol 1997; 22:47–51. 28. Laine FJ, Smoker WR. The ostiomeatal unit and endoscopic surgery: anatomy, variations, and imaging ﬁndings in inﬂammatory diseases. Am J Roentgenol 1992; 159:849–857. 29. Collet S, Bertrand B, Cornu S, Eloy P, Rombaux P. Is septal deviation a risk factor for chronic sinusitis? Review of literature. Acta Otorhinolaryngol Belg 2001; 55:299–304. 30. Erdem T, Aktas D, Erdem G, Miman MC, Ozturan O. Maxillary sinus hypoplasia. Rhinology 2002; 40:150–153. 31. Salib RJ, Chaudri SA, Rockley TJ. Sinusitis in the hypoplastic maxillary antrum: the crucial role of radiology in diagnosis and management. J Laryngol Otol 2001; 115:676–678. 32. Driben JS, Bolger WE, Robles HA, Cable B, Zinreich SJ. The reliability of computerized tomographic detection of the Onodi (Sphenoethmoid) cell. Am J Rhinol 1998; 12:105–111. 33. McAlister WH, Parker BR, Kushner DC, Babcock DS, Cohen HL, Gelfand MJ, Hernandez RJ, Royal SA, Slovis TL, Smith WL, Strain JD, Strife JL, Kanda MB, Myer E, Decter RM, Moreland MS. Sinusitis in the pediatric population. American College of Radiology. ACR Appropriateness Criteria. Radiology 2000; 215(suppl):811–818. 34. Benninger MS, Sedory Holzer SE, Lau J. Diagnosis and treatment of uncomplicated acute bacterial rhinosinusitis: summary of the Agency for Health Care

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SECTION II. ANATOMY AND PATHOPHYSIOLOGY

5 Anatomy and Physiology of the Paranasal Sinuses John H. Krouse and Robert J. Stachler Department of Otolaryngology Head and Neck Surgery, Wayne State University, Detroit, Michigan, U.S.A.

INTRODUCTION A thorough understanding of the functional anatomy and physiology of the nose and paranasal sinuses is essential in approaching the diagnosis and treatment of sinonasal diseases in children and adults. By considering the sequential development of the sinuses with maturation and the intricate anatomic and physiological mechanisms that are involved in the function of the sinuses in disease and in health, clinicians will be able to apply these principles in the effective management of sinonasal pathology. The present chapter will ﬁrst review the embryology of the developing nose and sinuses, and discuss their developmental anatomy throughout childhood (Table 1). It will also present the anatomy of the adult nose and sinuses in detail, with Table 1 Developmental Anatomy of the Sinuses in Childhood Sinus

Develops by

Radiographically present by

Completed development by

Ethmoid Maxillary Frontal Sphenoid

In fetal life In fetal life Age 1 or 2 Age 3 or 4

Soon after birth Soon after birth Age 3–6 Age 8 or 9

12 years of age 12 years of age 18 years of age Young adulthood

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a focus on how these anatomical features affect the sinonasal functions. Finally, it reviews the relevant aspects of the normal physiology of the nose and sinuses, and discusses how alterations in these normal physiological mechanisms can result in acute and chronic diseases in children and adults. EMBRYOLOGY OF THE NOSE AND PARANASAL SINUSES The ﬁrst nasal structures are seen as paired lateral nasal placodes and the midline frontonasal process by the fourth week of fetal life (1). These nasal placodes will eventually develop into the nasal cavities and their mucosal linings. The frontonasal process will become the nasal septum. The nasal placodes will invaginate to form pits that will extend back to the nasopharynx to deﬁne the nasal cavities (Fig. 1). The initial development of the paranasal sinuses is attributable to the formation of the lateral nasal wall ridges known as ethmoturbinals (2). These ethmoturbinals develop throughout fetal life into the various processes that will form the mature ethmoid bone. In the seventh to eighth week of development, ﬁve to six ridges begin to appear. Three to four of these ridges will persist in the mature ethmoid bone. The ﬁrst ethmoturbinal regresses and its ascending portion form the agger nasi. The descending portion forms the uncinate process. The second and third ethmoturbinals form the middle turbinate and the superior turbinate, respectively. The fourth and ﬁfth ethmoturbinals form the supreme turbinate. In contrast to the ethmoid structures described above, the inferior turbinate arises from a ridge, the maxilloturbinal, which is located inferior to those structures. It is thus formed from the maxillary bone. The nasal meati and recesses develop from primary furrows that lie between the ethmoturbinals (Fig. 1). The furrow between the ﬁrst and second ethmoturbinals is called the primary furrow. Its anterior segment develops into a portion of the frontal recess. The posterior (descending) portion develops into the ethmoid infundibulum, hiatus semilunaris, and the middle meatus. The maxillary sinus primordium develops from the inferior aspect of the ethmoid infundibulum. The second and third furrows form the superior meatus and the supreme meatus, respectively. The ethmoturbinals cross the ethmoid complex to attach to the lamina papyracea of the orbit and skull base. There are numerous furrows that become invaginations or evaginations. Ultimately, these furrows will develop into the ethmoid labyrinth. The secondary concha or accessory concha of the middle meatus are the names given to the evaginations. Invaginations are called secondary furrows or accessory meati of the middle meatus. The ethmoid bulla arises from a secondary lateral nasal wall evagination. The suprabulbar and retrobulbar recesses (sinus lateralis) arise from secondary furrows forming above and behind the ethmoid bulla. The maxillary sinus thus develops from a bud of the infundibulum. The bud continues to enlarge throughout fetal development. At birth, its

Figure 1 Development of the fetal face, frontal view, at: (A) four to ﬁve weeks, (B) ﬁve to six weeks, and (C) seven to eight weeks. Source: From Ref. 3.

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size is estimated to be 6 to 8 cm3 (Fig. 2). At four to ﬁve months after birth, the sinus can be seen radiographically as a triangular area medial to the infraorbital foramen. Rapid growth begins and continues until age three when growth slows until the seventh year. Growth of the maxillary sinus then accelerates until the sinus approximates adult size at age 12. Complete development ends in the late teens (Fig. 3) (3).

Figure 2 Nasal development, ventral view, at: (A) six to seven weeks, (B) seven to eight weeks, and (C) eight to nine weeks. Source: From Ref. 3.

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Figure 3 Development of the maxillary and frontal sinuses at various ages. Source: From Ref. 3.

Frontal sinus and frontal recess development is more varied. Debate still exists regarding the exact details. Three theories have been promoted. The frontal sinus may arise (1) from direct extension of the frontal recess, (2) from an anterior ethmoid cell, or (3) from the anterior superior aspect of the ethmoid infundibulum. The frontal sinus is barely perceptible at age one. Development of the frontal sinus does not characteristically begin until about the fourth year. Its adult size is attained at nearly age 12. The sinus continues to develop until the late teens. A cartilage capsule surrounds the primordial nasal cavity and is responsible for the bony development of this region. The uncinate process begins to form by the 10th to 12th week as a bud of cartilage. By the 13th to 14th weeks, a lateral space develops that becomes the ethmoid infundibulum. At 16 weeks, the future maxillary sinus begins to form from the infundibulum. The cartilage will resorb or ossify, depending on its location. The ethmoid sinus can be visualized radiographically at birth; however, its visualization is more difﬁcult than the maxillary sinuses. The ethmoid and the maxillary sinuses are the only sinuses to be sufﬁciently developed at birth to be clinically signiﬁcant in the pathogenesis of acute rhinosinusitis. The ethmoid sinuses continue to develop and are more readily seen at one year of age. By age 12, they have reached their adult size.

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The sphenoid sinus is the last sinus to develop. The posterior nasal capsule is invaginated by nasal mucosa at three to four months of fetal growth. This area enlarges to become a pouch or cavity called the cartilaginous copular recess of the nasal cavity. When the walls around the cartilage ossify, it is referred to as the ossiculum Bertini. This ossiﬁcation occurs in the later months of fetal development. The cavity does not deﬁnitely become the sphenoid sinus until the cartilage is resorbed as the ossiculum Bertini becomes attached to the sphenoid in the second to third year. Only in the sixth to seventh year does the sphenoid become pneumatized. Complete pneumatization does not occur until the 9th to 12th years. Further minor modiﬁcations of the sphenoid sinus occur until the late teens or into early adult life (Fig. 4). ANATOMY OF THE NOSE AND PARANASAL SINUSES Understanding the relationship of the bony anatomy of the face and the pneumatized cells within this bony framework is essential in appreciating the anatomy of the paranasal sinuses. The structures that make up the framework of the face include the nasal bones and cartilages, the ethmoid bones, the maxillary bones, and the frontal and sphenoid bones. The outer structure of the nose is formed by the paired nasal bones, as well as the upper lateral and lower lateral cartilages inferiorly. These structures provide prominence to the nasal pyramid, as well as allowing for an aperture to provide airﬂow through the nasal cavity (Fig. 5). The midline of the nose consists of a structure known as the nasal septum. This structure is composed of both bone and cartilage, and divides the nasal cavity roughly into two equal halves. The anterior portion of the nasal septum is composed of the quadrilateral cartilage, while the more posterior portion of the septum is composed of the perpendicular plate of

Figure 4 Development of the sphenoid sinus at various ages. Source: From Ref. 3.

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Figure 5 Coronal view of the paranasal sinuses. 1. Frontal sinuses. 2. Ethmoid sinuses. 3. Maxillary sinuses. 4. Nasal septum. 5. Superior turbinate. 6. Middle turbinate. 7. Inferior turbinate. 8. Eustachian tube. 9. Middle ear. 10. Nasolacrimal duct.

the ethmoid bone superiorly and the vomer inferiorly. At its posterior limit, the vomer ends at the posterior choanae of the nose. The lateral nasal wall consists of bony prominences covered with respiratory epithelium that project into the nasal cavity. These prominences are known as the nasal turbinates (Fig. 6). There is a space that exists under each of these turbinates that is described as the meatus. There are usually three turbinates and three meati present in the lateral nasal wall bilaterally. The largest of these turbinates is the inferior turbinate, which arises from the maxillary bone and projects into the nasal cavity. In the underlying inferior meatus, the nasolacrimal duct opens into the nose at the valve of Hassner. The middle turbinate is a projection of the ethmoid bone into the nasal cavity. The associated middle meatus is important in understanding paranasal sinus anatomy and physiology because it is into this meatus that the anterior sinuses communicate with the nose. More superiorly, a small superior turbinate is usually present in the nose, and forms the medial wall of the posterior ethmoid sinuses. In the associated superior meatus is an area referred to as the sphenoethmoidal recess, which is an important region in that the posterior ethmoid sinuses and sphenoid sinuses communicate with the nose in this location. The superior portion of the nose is bounded by a portion of the skull base that is referred to as the cribriform plate. This thin bony plate extends from the sphenoid sinuses posteriorly to the frontal recess anteriorly. The perpendicular plate of the ethmoid attaches in the midportion of this structure. The cribriform plate is perforated by branches of the olfactory nerve that terminate

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Figure 6 Sagittal view of the nose, paranasal sinuses, Eustachian tube, and middle ear.

within the nose to provide sensory input to the olfactory cortex. The cribriform plate is very thin, usually measuring only 1 to 2 mm in thickness (4). Ethmoid Sinuses The primary structure that forms the foundation for the bony anatomy of the face and sinuses is the ethmoid bone. The ethmoid bones are bilateral and are bound in the midline by the perpendicular plate. The superior boundary of the ethmoid bones is the cribriform plate, and the lateral boundary is the lamina papyracea, a thin bony plate that separates the ethmoid sinuses from the orbits laterally. Inferiorly, the ethmoid bone includes the middle turbinates and the lateral nasal wall at the area in which it fuses with the maxillary bone inferiorly. The lamina papyracea is an important structure in that it forms the barrier between the ethmoid sinuses and the orbits. This lamina is very thin and can be compromised by a variety of processes that originate within the ethmoid sinuses. Acute infections of the ethmoid sinuses can easily cross this thin bony barrier, resulting in periorbital or orbital cellulitis or abscess formation. Inﬂammatory masses of the ethmoid sinuses, such as mucoceles, mucopyoceles, and neoplasms, can also compromise this barrier through erosion or expansion, resulting in orbital injury. The anatomy of the ethmoid sinuses is complex, due to the variable pneumatization that occurs within the ethmoid bone during early development. The ethmoid sinuses can be best conceptualized as a cluster of cells

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that are divided into discrete anatomic regions by a series of vertical bony partitions. The cluster of cells that occurs within each ethmoid bone numbers in the range of 12 to 18 cells and is often referred to as the ethmoid labyrinth. The pneumatized cells of the ethmoid sinuses can be grouped into two functional units: the anterior ethmoid cells, which are more numerous and smaller in size and which communicate with the nose in the middle meatus, and the posterior ethmoid cells, which are less numerous, larger, and communicate with the nose in the sphenoethmoidal recess. The ethmoid sinuses are apparent by the third to fourth month of fetal life, and can be appreciated radiologically during the ﬁrst year of life. The anterior ethmoid cells, along with the frontal sinus and the maxillary sinus, communicate with the nose through an anatomic region that is referred to as the ostiomeatal complex (OMC) (Fig. 7). The OMC is important as a structural unit, in that this area is commonly conceptualized as of primary importance in the normal functioning of the anterior paranasal sinuses. When the structural integrity of the OMC is compromised and the normal ventilation and drainage of the sinuses is adversely affected, it is common for the associated sinuses to become secondarily infected.

Figure 7 Coronal CT radiograph of the paranasal sinuses with ostiomeatal complex outlined. 1. Middle meatus. 2. Uncinate process. 3. Middle turbinate. 4. Ethmoid sinuses. 5. Maxillary sinuses. 6. Frontal recess. 7. Middle turbinate. Dashed lines outline the area of the infundibulum and OMC. Abbreviation: OMC, ostiomeatal complex.

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The posterior ethmoid sinuses are composed only of several larger air cells. Posteriorly, the ethmoid sinuses are contiguous with the rostrum of the sphenoid sinus. Occasionally a single large posterior ethmoid cell will pneumatize posteriorly and laterally to the sphenoid sinus. This sphenoethmoidal or Onodi cell is of importance in that the optic nerve travels along its lateral aspect and can often be dehiscent. Maxillary Sinuses The maxillary bones are bilateral structures that form the projection of the anterior face. The maxilla consists of a main body and four processes: the frontal, orbital, alveolar, and palatal processes. It forms the midface and provides support for the maxillary teeth. The opening of the nasal cavity enters anteriorly through the maxillary bone at the nostrils bilaterally. The right and left maxillary bones are contiguous in the midline below the nose, and their palatal processes extend centrally to form the anterior portion of the hard palate. The oral cavity is separated from the nose and maxillary sinuses by this process. The alveolar processes of the maxillary bones contain the roots of the maxillary teeth. The orbital processes of the maxillary sinuses make up the medial portion of the ﬂoor of the orbit and support the orbital contents inferiorly. The roof of the maxillary sinuses, therefore, is bilaterally contiguous with the orbital ﬂoor. Within the maxillary bones are the maxillary sinuses, the largest of the four pairs of paranasal sinuses (Fig. 8). These sinuses are well developed at birth and are extensively pneumatized. They are apparent by the third to fourth month of fetal life, and can be appreciated radiologically during the ﬁrst year of life. The maxillary sinuses are surrounded on all sides by bony walls. The medial wall of the maxillary sinus has an opening between the maxillary sinus and the nose, referred to as the maxillary ostium. This opening provides the normal communication between the maxillary sinuses and the nasal cavity, and it is through this small ostium that the maxillary sinus is both drained and ventilated. The ostium is a small opening into the ethmoid infundibulum that is located high on the medial wall of the maxillary sinus, about in the midportion of the anterior–posterior plane. This ostium is not normally visible, as it is lateral to the uncinate process of the ethmoid bone. There are also areas in the medial wall of the maxillary sinuses where there is the absence of bone and a membranous area separates the nose from the sinuses. These areas are referred to as fontanelles, and while more commonly found in the posterior portion of the medial wall, can also be present more anteriorly as well. Frontal Sinuses The superior portion of the face and anterior portion of the skull is composed of a large, ﬂat bone referred to as the frontal bone. The frontal

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Figure 8 Coronal view of the four pairs of paranasal sinuses.

bone forms the contour of the forehead and the ﬂoor of the anterior cranial fossa. It is contiguous with the zygoma laterally and forms the roof of the orbits medially. It divides into two tables in the forehead, the anterior and posterior tables, which contain the pneumatized space referred to as the frontal sinus. The anterior table is palpable and visible as the forehead, while the posterior table forms the anterior wall of the anterior cranial fossa. The frontal sinuses are of variable size and development. They are absent in up to 10% of individuals. While the average size of each frontal sinus is about 10 cc, an individual sinus can be much larger. The natural ostia of the frontal sinuses are found inferomedially, near the midline septum between the right and left sinuses. They communicate with the nose through an inverted funnel-shaped region known as the frontal recess. This area can be narrowed by large ethmoid cells that sometimes interfere with normal ventilation and drainage of the frontal sinuses. The frontal bones are not pneumatized until the ﬁrst or second year of life, and their deﬁnitive shape is not apparent until the third year of life. The frontal sinuses become pneumatized during this period, and are apparent as discrete structures between three and six years of age. They continue to enlarge as frontal pneumatization increases through adolescence.

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Sphenoid Sinuses Within the center of the skull is the sphenoid bone. This structure forms the major portion of the central skull base, as well as portions of the orbit, lateral skull, and cranial ﬂoor. Superiorly to the sphenoid bone is the sella turcica and middle cranial fossa. Within the midportion of the sphenoid bone are the sphenoid sinuses, small pneumatized spaces measuring 5 to 10 cc in size, that pneumatize in childhood and often do not complete their pneumatization until early adult life. These sinuses communicate with the nasal cavity in the sphenoethmoidal recesses bilaterally. The natural ostium of the sphenoid sinus is located in the anterior wall of the sphenoid bone at a location near the superior aspect of the sinus. This opening is at the inferomedial edge of the superior turbinate, in a narrow space along the sphenoid rostrum and lateral to the nasal septum. The sphenoid sinuses are the ﬁnal sinuses to pneumatize. They begin as an invagination in the nasal capsule, but are not recognizable as discrete units until age three or four. They are not radiographically apparent until age eight or nine, and continue to develop into young adulthood as the sphenoid bone completes its pneumatization. PHYSIOLOGY OF THE NOSE AND PARANASAL SINUSES The function of the nose is to allow inspired air to enter the upper respiratory system and to be delivered to the tracheobronchial tree. The presence of the turbinates on the lateral nasal walls allows this airﬂow to be turbulent, creating eddies in ﬂow as the air moves posteriorly from the nostrils to the posterior choanae. This ﬂow pattern directs the inspired air to come into contact with a large surface area of the nasal mucosa as it moves posteriorly, which allows three physiological functions during ﬂow: ﬁltration, warming, and humidiﬁcation (5) (Table 2). The mucosa of the nasal cavity is a respiratory-type pseudostratiﬁed columnar epithelium. This epithelium is contiguous with the paranasal sinuses, and it is lined with a surface layer of cilia. The ciliated surface is involved in a variety of processes, including the transport of mucus and particulate matter from the nasal cavity into the nasopharynx, where it can be swallowed. This process is known as mucociliary clearance, and is an essential component of the normal physiology of the nose and paranasal sinuses. As mucus is produced by goblet cells in the nasal mucosa, this mucus forms a blanket that lines the surface of the nasal epithelium. This mucous blanket is involved in ﬁltration of particulate matter as it enters the nose. This particulate population can be composed of viral and bacterial organisms; foreign proteins such as animal dander, dust mite debris, and pollen grains; and irritants such as tobacco smoke. The ﬁltration and transport of this particulate mass is necessary for normal sinonasal function. When mucociliary clearance mechanisms are disrupted, as from allergic or infectious rhinosinusitis, changes can occur in the underlying mucosa that can lead to chronic dysfunction and disease.

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Table 2 Functions of the Nose and Sinuses Filtration Removal of particulate matter Transport of foreign organisms, irritants, and allergens Prevention of large particles from reaching the lower airway Warming Increasing temperature of inspired, cold air Delivering warm air to the lower airway Humidiﬁcation Increasing humidity of inspired, dry air Delivering moist air to the lower airway Mucociliary clearance Movement of mucus blanket through the sinuses and nose Transport of mucus blanket to the pharynx Ventilation Increases oxygen tension in the sinuses Allows normal environment for respiratory epithelium

In addition to the ﬁltration function of the nasal cavity, the nose is involved in both the warming and humidiﬁcation of inspired air. The inhalation of warm, moist air into the lower respiratory tract is important in maintaining optimal function of the bronchopulmonary system. When this important function of the nose is inoperative, cold, dry air can be delivered to the lungs, which can increase the likelihood of acute bronchospasm, shortness of breath, and infection. Chronic nasal dysfunction can contribute signiﬁcantly to lower respiratory diseases such as asthma and chronic bronchitis. This mucociliary clearance mechanism is also present in the paranasal sinuses. Since the epithelium is the same throughout the upper respiratory system, the mucosa lining the sinus cavities also actively produces mucus that must be cleared into the nasopharynx and swallowed. Mucociliary clearance within the sinuses is genetically programmed in such a manner as to direct the ﬂow of mucus from the sinuses in a predetermined, predictable pattern from the interior of each sinus to the natural opening or ostium of the sinus, and into the nose itself (6). Disruptions in the normal clearance of mucus from the sinus chambers results in mucous stasis within the sinuses, which leads to a sequence of events that predisposes those sinuses to both acute and chronic dysfunction and infection. Ventilation of air into the sinuses and drainage of mucus from the sinuses is central in the normal physiologic function of the sinuses, and interference with this ventilation and drainage is a key component in the pathogenesis of acute and chronic rhinosinusitis (7). As was previously discussed, each of the sinuses communicates with the nasal cavity through a precise anatomical location. The anterior ethmoid and maxillary sinuses communicate with the nose through a common passage way, known as the OMC. Since the ethmoid infundibulum is the ﬁnal space

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through which these sinuses communicate with the nose, disease in the ethmoid is common in most cases of acute and chronic rhinosinusitis. For this reason, the ethmoid sinuses are often considered to be the ‘‘seat of sinus disease.’’ The frontal sinuses also communicate with the nose anteriorly, but their pattern of ventilation and drainage is somewhat variable. In about two-thirds of individuals, the frontal sinuses communicate with the ethmoid infundibulum directly, with the frontal recess opening lateral to the bulla ethmoidalis into the hiatus semilunaris superior. In the remaining one-third of individuals, the frontal recess communicates medial to the bulla, and opens directly into the middle meatus just lateral to the attachment of the middle turbinate. In both of these cases, however, the communication with the nose is through the middle meatus inferiorly. Both the posterior ethmoid sinuses and the sphenoid sinus communicate with the nose more posteriorly in an area known as the sphenoethmoidal recess. This area is in direct communication with the nasopharynx. While disease in the sphenoethmoidal recess is less frequent than that seen in the OMC, it is still quite common among patients with acute and chronic sinus infections. CONCLUSION An understanding of the embryology, developmental and adult anatomy, and physiology of the nose and paranasal sinuses is important in assisting clinicians with appropriate diagnosis and management of the patient with nasal and sinus diseases. Ongoing study of the intricate nature of sinonasal function in disease and in health can provide physicians with a better appreciation of these complex diseases, and can facilitate better outcomes in children and adults with acute and chronic rhinosinusitis. REFERENCES 1. Hengerer AS. Embryologic development of the sinuses. Ear Nose Throat J 1984; 63:134–136. 2. Van Alyea OE. Nasal Sinuses: an Anatomic and Clinical Consideration, 2nd ed., Baltimore: Williams & Wilkins, 1951. 3. Naspitz CK, Tinkelman DG. Childhood Rhinitis and Sinusitis: Pathophysiology and Treatment. New York: Marcel Dekker, 1990. 4. Kennedy DW, Bolger WE, Zinreich SJ. Diseases of the Sinuses: Diagnosis and Management. Philadelphia, BC: Decker, 2001. 5. Abramson M, Harker LA. Physiology of the nose. Otolaryngol Clin North Am 1973; 6:623–635. 6. Stamberger H. Functional Endoscopic Sinus Surgery: the Messerklinger Technique. Philadelphia, BC: Decker, 1991. 7. Corren J, Togias A, Bousquet J. Upper and Lower Respiratory Disease. New York: Marcel Dekker, 2003.

6 Pathophysiology of Sinusitis Alexis H. Jackman and David W. Kennedy Department of Otorhinolaryngology Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.

INTRODUCTION A complete understanding of the pathophysiology of rhinosinusitis remains elusive, but several infectious and inﬂammatory pathways have been identiﬁed. Microbial agents, such as viruses, bacteria, and fungus, are wellestablished etiologies of rhinosinusitis, especially in the acute situation, but numerous host and environmental factors have also been implicated, either individually or in combination in the chronic disease state. This chapter will discuss these various factors as well as the individual and symbiotic roles they play in the development of rhinosinusitis. Particular emphasis will be placed on current hypotheses regarding the etiology of chronic rhinosinusitis (CRS) and important new areas of research such as bioﬁlms, superantigens (sags), and osteitis.

Local Paranasal Sinus Defense Mechanisms The main function of the paranasal sinuses (PNS) is to eliminate foreign material and defend the body against infection. Essential local factors in maintaining normal paranasal sinus function include:

Ostiomeatal complex (OMC) patency Mucociliary transport Normal mucus production 109

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Figure 1 The ostiomeatal complex. Source: Kennedy DW. The concept of the ostiomeatal complex. Diseases of the Sinuses: Diagnosis and Management. Hamilton: B.C. Decker, 2001:197.

Ostiomeatal complex (OMC) is the common drainage site of the frontal, ethmoid, and maxillary sinuses. Although a myriad of variations in the size and architecture of the OMC exist, patency of this area and its respective outﬂow tracks is necessary for the removal of mucus and debris and maintenance of sufﬁcient oxygen tensions to prevent bacterial overgrowth. (Fig. 1). Recently, acknowledgment of an overemphasis on the role of OMC patency in CRS has been made, but nonetheless the OMC remains one of the several important factors in normal paranasal sinus function, and osteomeatal obstruction remains a common ﬁnal pathway in sinus disease becoming chronic. Another major factor in PNS function is mucociliary transport (MCT). MCT is dependent on both ciliary activity and the rheologic properties of the mucus. Characteristics of the cilia, such as their structure and population, as well as the coordination of their movement are important in their ability to function effectively. Likewise, mucus characteristics, such as

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Figure 2 Effects of elasticity and viscosity on mucociliary clearance. Source: Adapted from Ref. 1.

the volume that is secreted and its viscoelastic properties, are known to affect overall MCT, with maximal velocities being reported for mucus with an elasticity (G’) of about 20 dyn/cm2 and a viscosity (Z’) of 2 poise (1) (Fig. 2). Systemic Paranasal Sinus Defense Mechanisms Acquired and innate immunity are systemic defense mechanisms against infection in the sinonasal tract. Humoral immunity, which is a function of B-lymphocytes, is predominately mediated by IgA antibodies. Normal mucus contains large amounts of IgA, which detects and initiates the removal of foreign material through a process termed opsinization. Additional antibodies present in nasal mucosa include IgG and IgE. Although IgE is detected in only trace amounts in normal individuals, large increases in its relative concentration are observed in atopic patients with CRS, thereby implicating IgE as a participant in allergic CRS. IgG plays a less prominent role and is present

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only in minimal concentrations. Cell-mediated immunity involves activated T-lymphocytes, macrophages, and cytokines. Defensins are antimicrobial cytokines that are present in the airway surface liquid of the paranasal mucosa. The cationic defensin polypeptide binds to the outer membrane of target bacterial, viral, or fungal cells, causing membrane disruption, internalization of defensin, and ﬁnally cell death (2,3). In a study comparing the level of expression of defensins in control patients versus patients with chronic sinusitis, b-defensins were detected only in patients with sinusitis. Furthermore, levels of b-defensins were signiﬁcantly higher in nasal polyp (NP) tissue than in inferior turbinate tissue in these patients, supporting the role of this inﬂammatory mediator in the pathophysiology of CRS (4). Interruption of the normal functions of the PNS changes the physiological milieu and creates an environment that fosters microbial proliferation and initiates an inﬂammatory response. A combination of local and systemic factors are involved in normal sinus function. An example of this is given by Goldman et al. (5) in their description of the mucosal surface of the airway as a ‘‘chemical shield,’’ with the airway epithelium producing mucus-containing salt-sensitive defensins and the mucus having a low-salt (<50 mM NaCl) liquid on the surface that renders the defensins active. Interruption of any one of the many factors, involved in normal sinus functioning can impact other factors often initiating a cascade of events leading to CRS, with pathological changes in the sinuses that often begin in or are accompanied by similar changes in the nasal airway (5,6) (Fig. 3).

Figure 3 The pathological cycle of CRS.

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DEFINITIONS OF RHINOSINUSITIS Rhinosinusitis is an umbrella term that includes a continuum of inﬂammatory changes in both the nose and sinuses. Rhinosinusitis describes many different pathological processes that result in mucosal inﬂammation of the nose and PNS. In 1996, a multidisciplinary rhinosinusitis task force (RSTF) was formed in part to develop working deﬁnitions to describe the wide spectrum of pathological entities represented. The seminal article, ‘‘Adult Rhinosinusitis Deﬁned,’’ which summarized these proceedings, deﬁned ﬁve separate categories: acute, subacute, chronic, recurrent acute, and acute exacerbation of CRS. These categories were deﬁned according to speciﬁc major and minor signs and symptoms associated with rhinosinusitis and the time course over which they occurred without regard to their speciﬁc pathogenesis (7) (Table 1). Acute rhinosinusitis (ARS) was deﬁned by the presence of speciﬁc signs and symptoms for a duration of up to four weeks. Using similar clinical criteria, subacute rhinosinusitis was deﬁned as lasting between 4 weeks and 12 weeks, and recurrent acute rhinosinusitis was deﬁned by four or more episodes of acute sinusitis with complete symptom remission between episodes. CRS was deﬁned by the presence of several clinical symptoms for duration of at least 12 weeks, whereas patients with sudden worsening of persistent symptoms are classiﬁed as having an acute exacerbation of CRS. These deﬁnitions put forth by the RSTF are independent of hypothesized etiologies and associated disease states, reﬂecting its members’ view of CRS as an inﬂammatory disease of uncertain etiologies (7).

ACUTE RHINOSINUSITIS ARS is most commonly associated with an infectious etiology in both children and adults. The type and species of microorganism implicated has been shown to be age-related in several studies. In children, viral agents such as adenovirus, inﬂuenza virus, parainﬂuenza virus, and rhinovirus predominate, although bacterial agents are also common with the major pathogens being Streptococcus pneumoniae, non-typeable Haemophilus inﬂuenzae, and Moraxella catarrhalis (8,9). Similarly, S. pneumoniae, H. inﬂuenzae, and M. catarrhalis were also identiﬁed as the predominant microorganisms in cases of pediatric subacute rhinosinusitis (10). Anaerobic bacteria have not been shown to play a major role in pediatric rhinosinusitis. Wald et al. reported that only one of 47 sinus aspirates was positive for anaerobic bacteria (11). In adults, S. pneumoniae and non-typeable H. inﬂuenzae account for over 75% of cases of community-acquired acute sinusitis, and two bacterial species in high density were identiﬁed in 25% of cases. Although S. aureus and Streptococcus pyogenes are uncommon causes of ARS, they have been associated with serious suppurative processes such

Include in differential

4 episodes per year, Same as acute with each episode lasting 7 to 10 days and absence of intervening signs and symptoms of chronic rhinosinusitis

Recurrent acute

Same as chronic

4–12 weeks

Subacute —

Same as chronic

2 major factors, 1 1 major factor or 2 minor factors major factor and 2 minor factors, or nasal purulence on examination

Strong history

4 weeks

Duration

Acute

Classiﬁcation

Table 1 Classiﬁcation of Adult Rhinosinusitisa

Fever or facial pain does not constitute a suggestive history in the absence of other nasal signs or symptoms Consider acute bacterial rhinosinusitis if symptoms worsen after 5 days, if symptoms persist for > 10 days, or in presence of symptoms out of proportion to those typically associated with viral infection Complete resolution after effective medical therapy —

Special notes

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12 weeks

—

major factors, 1 major factor and 2 minor factors, or nasal purulence on examination —

1 major factor or 2 minor factors

—

Facial pain does not constitute a suggestive history in the absence of other nasal signs or symptoms

Rhinosinusitis may be clinically deﬁned as condition manifested by an inﬂammatory response involving in the mucous membranes (possibly including neuroepithelium) of nasal cavity and paranasal sinuses, ﬂuids within these cavities, and/or underlying bone. Fluids within these cavities are dynamic and are related to dynamic pathologic changes in bone and soft tissues of nasal cavity and paranasal sinuses. Symptoms associated with rhinosinusitis include nasal obstruction, nasal congestion, nasal discharge, nasal purulence, postnasal drip, facial pressure and pain, alteration in sense of smell, cough, fever, halitosis, fatigue, dental pain, pharyngitis, otologic symptoms (e.g., ear fullness and clicking), and headache.

a

Acute exacerbations of Sudden worsening of chronic chronic rhinosinusitis, with return to baseline after treatment

Chronic

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as orbital and intracranial abscesses. Furthermore, anaerobic bacteria are also rarely implicated in ARS in adults, and when they are, they are almost always associated with a primary dental pathology (12). The pathophysiologic reaction to infectious agents in ARS is the initiation of an inﬂammatory response, the intent of which is to promote the removal of foreign material, interrupt inﬂammatory cascade, and restore normal sinus function. On a macroscopic level, pathologic changes include mucosal edema with inﬁltrates of lymphocytes and plasma cells and loss of cilia from the respiratory epithelium. Luminal exudates are also found, which consist of primarily neutrophils and limited amounts of eosinophils (13–15). Several inﬂammatory cytokines have been demonstrated in conjunction with these histopathologic changes. Cytokines such as IL-1B, IL-6, and TNF-a are important in inducing the expression of adhesion molecules and activating endothelial cells and T-lymphocytes. Subsequently, these activated T-lymphocytes release IL-8, a neutrophil chemotaxic factor, which further enhances the inﬂammatory response and eventually leads to evacuation of the initiating organism (16–19). As the infection resolves, the inﬂammatory reaction subsides and the physiologic state is restored. CHRONIC RHINOSINUSITIS The speciﬁc pathogenesis of CRS remains to be determined. Although in some cases it may result from a persistent acute infection. It is thought to arise from multiple heterogeneous etiologies either independently, or more likely, in combination. The latest publications of chronic rhinosinusitis task force (CRTF) emphasize the position that it is the resulting end-stage inﬂammatory state that deﬁnes this disease. Furthermore, the concept of an integrated airway syndrome has been hypothesized along with rhinitis, rhinosinusitis, and asthma as a spectrum of manifestations of this single disease state (8). In contrast to ARS, the etiology of CRS is thought to be more multifactorial with the contribution of several systemic host, local host, and environmental factors. Systemic host factors include genetic predisposition, immunosuppression, and primary ciliary dyskinesia (PCD). Local host factors include anatomical sinus obstruction or local tumors or masses obstructing the sinuses, and localized persistent inﬂammation, such as that in the case of bony inﬂammation. Environmental factors include bacteria, viruses, and fungi, as well as pollution, smoking, and allergy. Several microorganisms, such as bacteria and fungi, are associated with CRS, but additional research in this area is necessary to more clearly deﬁne their relative roles. Further understanding of these factors may provide new approaches to diagnosis and treatment of this disease. The pathological mechanisms involved in CRS share many similarities with those of ARS, although distinct differences have been demonstrated.

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The gross pathological expression of CRS is more variable, and has been divided into two major categories—CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP is characterized by extensive mucosal edema with goblet cell hyperplasia and mononuclear cell inﬁltration, whereas CRSsNP is often noted to have epithelial damage with very limited neural structures and goblet cell hypoplasia. Fibrosis is common in both, but occurs to a greater extent in CRSwNP (20,21). An increased number of eosinophils is the predominant difference in the cellular inﬁltrate between CRSwNP and CRSsNP. Also, increased local production of IgE has been reported (22). A wide variety of inﬂammatory mediators have been demonstrated to be increased in patients with CRSsNP and include IL-1, IL-6, IL-8, TNF-a, GM-CSF, ICAM-1, MPO (myeloperoxidase), and ECP (eosinophilic cationic protein) (23–26). Patients with nasal polyposis (NP) have also been shown to have increased amounts of these mediators, but additional inﬂammatory mediators in the subset of patients with NP include a subset of the IL-8 superfamily referred to as regulated on activiation- normal T expressed and secreted (RANTES) as well as IL-4 and IL-5, which have been shown to directly activate and increase the survival of eosinophils (27,28). ETIOLOGIES OF CHRONIC RHINOSINUSITIS A myriad of potential factors predispose an individual to the development of CRS, and several classiﬁcation schemes have been developed to assist in the understanding of the relationship between these factors. One approach to the variety of proposed etiologies is to divide them into three categories: systemic factors, local host factors, and environmental factors (Table 2). Systemic Host Factors Genetic/Congenital Disorders Several systemic host factors contribute to the development of CRS. Genetic abnormalities such as cystic ﬁbrosis (CF) and primary ciliary disorders are intimately associated with CRS. Although these diseases are commonly diagnosed during childhood, adults with a lifelong history of CRS associated with bronchial infection, infertility, or situs inversus should be further evaluated (29). In patients with CRS, diagnosis of a primary ciliary disorder usually requires a tracheal biopsy because, intranasally, the acquired ciliary deformities associated with CRS can be difﬁcult to differentiate from the congenital variant. CF is one of the most common hereditary diseases and affects approximately 30,000 people in the United States, having a gene frequency of 1 in 20–25 (30,31). The disease was mapped to the long arm of chromosome 7 (7q31), which encodes a protein product that acts as a chloride channel. Genetic alterations of this protein allow for increased water absorption from

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Table 2 Etiologic Factors in Chronic Rhinosinusitis Systemic host factors Genetic/congenital conditions—cystic ﬁbrosis (CF), primary ciliary disorders (PCD) Immunodeﬁciencies/immunosuppression—HIV, iatrogenic-s/p transplant, chemotherapy Autoimmune— Granulomatosis (sarcoid, Wegener’s) Vasculitis (SLE) Idiopathic—Samter’s syndrome Local host factors Anatomic abnormalities Bony inﬂammation Neuromechanisms Mucoceles Neoplasms (benign and malignant) Environmental factors Infectious—bacterial, fungal, bioﬁlms, superantigens Allergy—IgE-mediated, non-IgE-mediated hypersensitivities Pollutants—pollution, smoke, dust, volatile organic compounds

the respiratory cells, resulting in increased viscosity and impaired mucociliary clearance (32). Furthermore, bacterial colonization and infection with Pseudomonas aeruginosa, H. inﬂuenzae, and anaerobes are frequent and thought to induce cellular changes such as goblet cell hyperplasia, loss of cilia, and squamous cell metaplasia. Gross pathological changes include nasal polyposis, which is usually noted in early childhood. In contrast to atopic patients, NP in patients with CF is not associated with a thickened basement membrane and an eosinophilic inﬁltrate (33). Other gross pathological changes include osteomeatal obstruction secondary to local inﬂammation and tenacious mucus (34). Recently, there has been signiﬁcant interest in whether minor CF variations may be a factor in CRS. At this point, the evidence for this is limited. However, some patients with homozygous CF do present only with CRS, and CF should be suspected in any patient who has had an operation before the age of 18 years (35). Another group of genetic disorders commonly associated with CRS is termed primary ciliary disorder (PCD), which include Kartagener’s syndrome, immotile cilia syndrome, ciliary dysmotility, and primary ciliary orientation defects. Although it is rare with a prevalence of approxiamately 1:20,000, the effects on the sinonasal tract are signiﬁcant (36). PCD is hypothesized to be a genetically heterogeneous condition as several loci on various chromosomes have been identiﬁed. Abnormalities in ciliary structure resulting in malfunction characterize this disorder and include a number of ultrastructural alterations in the ciliary architecture, which range from complete ciliary aplasia to defects in ciliary orientation (37–39).

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Resulting mucus stasis leads to pathological mechanisms similar to CF in the development of CRS. Immunodeficiency Diseases Chronic medically refractive CRS is common in patients with congenital and acquired immunodeﬁciencies, as well as those who are immunosupressed. IgG deﬁciencies are the most common cause of immunodeﬁciencies associated with CRS (40). CRS frequently occurs in patients with the human immunodeﬁciency virus, with a reported rate of 68% of patients with this disease (41). Endoscopic surgery has been advocated as a treatment for patients who meet the surgical criteria for surgery regardless of their CD4 count (42). CRS is also commonly diagnosed in patients receiving chemotherapy and in patients being treated with long-term immunosuppressive therapies, such as in post-transplant recipients. Furthermore, speciﬁc types of immunodeﬁciency syndromes are associated with certain infectious pathogens. Patients with antibody deﬁciencies are known to have a predisposition to infections with encapsulated aerobic gram-positive organisms as well as gram-negative organisms. In contrast, CRS patients with T-cell deﬁciencies is associated with fungal, viral, and protozoal organisms. In patients with complement deﬁciencies, aerobic gram-negative organisms predominate. Autoimmune/Idiopathic Diseases CRS is associated with several autoimmune or idiopathic diseases and may be their presenting illness. Granulomatous disorders frequently associated with CRS include sarcoidosis and Wegener’s granulomatosis (WG). Sarcoidosis, a chronic granulomatosis disease of unknown etiology, can involve the upper respiratory tract, although lower respiratory tract involvement is more common. The pathological hallmark of this disease is a chronic inﬂammatory response, which includes non-caseating granulomas. Local tissue changes range in severity from destruction of cilia and mucus-producing glands to local tissue destruction (43). WG is a necrotizing granulomatosis of the upper and lower respiratory tract, and is currently classiﬁed as one of the antineutrophil cytoplasmic antibodies (ANCA)-associated small vessel vasculitides. WG is characterized by autoantibodies to proteinase 3, a component of neutrophil azurophilic granules, although their detection is not required for diagnosis (44,45). Sinonasal manifestations, and therefore CRS, is common in this population and can be severe. Other vasculitides associated with CRS include systemic lupus erythematosus, Churg–Strauss vasculitis, relapsing polychondritis, and Sjogrens syndrome (46). Samter’s syndrome, the triad of nasal polyps, bronchial asthma, and intolerance to aspirin, is a condition of unknown etiology, which is associated with an early onset of CRS. Typically, these patients present between the ages of 20 and 30 years with nasal congestion and polyposis that respond poorly to medical and

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Figure 4 Coronal CT view of frontal sinus and sagittal MRI view of a patient with Samter’s triad. Note: Sinus opaciﬁcation and erosion of anterior and posterior table bone.

surgical management, although they may also present with asthma later in life (47). Although a genetic component of this syndrome has been suggested, few studies to date have been conducted (Fig. 4). Local Host Factors Anatomic Abnormalities Local host factors can also play a role in the development of CRS. Anatomic abnormalities of the sinuses, particularly those causing obstruction or narrowing of the OMC either chronically or intermittently due to an acute inﬂammatory response, can be associated with CRS. Moreover, since the OMC is immediately adjacent to the site where the majority of inhaled particulate matter is deposited, it is one of the most common sites for mucosal inﬂammation. Obstruction in the area of the OMC will result in secondary obstruction of the dependent maxillary and frontal sinuses, and persistent inﬂammation of the OMC can result in persistent or recurrent infections (Fig. 5). The relative contribution of anatomic abnormalities to the development of CRS is controversial. The rate of structural sinonasal variations on CT scans has not been shown to correlate with the rates of development of CRS (48). However, it appears reasonable that anatomical variations, such as a markedly deviated nasal septum and aerated middle turbinate (concha bullosa), both of which narrow the OMC, may predispose to muco-

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Figure 5 Diagram of ostiomeatal complex with concha bullosa. Source: Cummings CW: Otolaryngology – Head and Neck Surgery, Update 1, Chapter 4: Kennedy DW, Zinreich SJ: Endoscopic Sinus Surgery, page 83, ﬁgure 4–4, CV Mosby Co. 1989.

ciliary obstruction, subsequent infection, and CRS in patients who also have other risk factors for CRS. Also, it has been demonstrated that certain anatomical abnormalities were associated with the degree and rate of ethmoid, maxillary, and sphenoid sinus opaciﬁcation as determined by CT scan during an upper respiratory tract infection. These anatomical abnormalities included septal deviation, horizontal processes of the uncinate, concha bullosa, and Haller cell pneumatization (49). Iatrogenic Anatomic Abnormalities Previous surgery and sinonasal trauma may also predispose to sinusitis as a result of malpositioning and scarring of the sinonasal structures, particularly within the region of the OMC. In a review of the causes of failure of endoscopic sinus surgeries, Richtsmeier reported obstructed natural ostia and mucus maltransport among the ten most common reasons for persistent disease (50).

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Sinonasal Cysts, Mucoceles, and Neoplasms Local obstruction of the PNS by benign cysts, mucoceles, as well as benign and malignant neoplasms, can result in rhinosinusitis. Although mostly asymptomatic, mucous retention cysts that result from the blockage of seromucinous glands in the sinus respiratory epithelium can lead to sinus obstruction and CRS; mucoceles, expanding mucus-ﬁlled cysts that are lined by entrapped respiratory epithelium, are frequently associated with symptoms of unilateral CRS such as sinus tenderness and headache. Mucoceles commonly arise from an obstructed sinus ostium or sinus septation or from sequestered sinus epithelium a sinus fracture site. If superinfection occurs, a mucopyocele is produced. Sinus neoplasms, such as juvenile nasopharyngeal angioﬁbroma, inverting papilloma, and various carcinomas, typically present with unilateral nasal obstruction, but may also present with symptoms of unilateral CRS or recurrent ARS, sometimes associated with epistaxis. Accordingly, tumors need to be considered in the differential diagnosis of etiology of this disease (51,52). Persistent Inflammation/Osteitis Persistent inﬂammatory changes within the paranasal sinus bones is another local host factor associated with CRS. Investigations into the role that bony inﬂammatory changes play in CRS has begun recently. Histological, and radiographical changes in the bone are commonly termed ‘‘osteitic changes,’’ and current research focuses on determining whether or not these areas are a potential source of persistent inﬂammation. Using histomorphometry and radioactive labeling bone studies, the rates of bony turnover in patients with CRS was found to be markedly increased and comparable to that of patients with osteomyelitis (53) (Fig. 6). Although these ﬁndings raise the possibility that bacteria may be present in these areas, PCR studies have yet to conﬁrm their presence. In studies of pseudomonas-induced maxillary sinusitis using a rabbit model, inﬂammatory changes in the bone were noted not only in the adjacent regions but also distally, apparently from spread through the Haversian canals (54). Additional studies by Khalid et al. using Pseudomonas and S. aureus-induced maxillary sinusitis have demonstrated similar results of increased vascularity, inﬂammatory inﬁltrates, and later ﬁbrosis occurring in the canals of the Haversian system (55). In summary, there is clear evidence that the bone becomes involved in the disease process in CRS and that, at least in rabbits, the inﬂammation in the bone may be present at a site away from the primary infection. The pathological changes seen are histologically compatible with chronic osteomyelitis, but no organisms have been identiﬁed within the bone. Although it appears very likely that this inﬂammation within the bone contributes signiﬁcantly to the refractory nature of the disease process, this has not

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Figure 6 Bony Remodeling in CRS. Tetracycline-labeled ethmoid bone at the time of surgery in a control patient without evidence of infection (A) and in patients with chronic sinusitis (B). Two doses of tetracycline were given 14 days apart. (A) There is one line labeling, indicating little bone turnover. (B) There is marked separation of the two lines of ﬂuorescence, indicating signiﬁcant bone remodeling within the 14-day period. Source: Kennedy DW. Diseases of the Sinuses: Diagnosis and Management. Hamilton: B.C. Decker, 2001: 197.

yet been proven. Continuing work in this area will help to better deﬁne the pathophysiology of bony inﬂammation. Environmental Factors Microorganisms Bacterial infections: Several prospective and retrospective studies have been conducted to assess the microbiological etiologies of CRS in both children and adults. Infectious pathogens such as H. inﬂuenzae, S. pneumoniae and M. catarrhalis, account for up to 55% of cases in pediatric CRS. The

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relative contribution of anaerobic bacteria has been debated, and the large variations in rates of isolation have been attributed to culture techniques. Brook reported that up to 50% of cases of CRS were culture-positive for anaerobic bacteria, with the predominance of Prevotella, Fusobacterium, and Peptostreptococcus spp. (56,57). In adults, infectious CRS is commonly polymicrobial, and both gram-positive and gram-negative aerobic and anaerobic bacteria are frequently isolated. A wide variety of aerobic bacteria, such as coagulase negative Staphylococcus, S. aureus, Streptococcus viridans, P.aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Enterobacter spp. have been isolated. Also, several different anaerobic species have been demonstrated, including Prevotella, Fusobacterium, and Peptostreptococcus spp. (56–64). Bioﬁlms. Bioﬁlms are sessile bacterial microcolonies that are enclosed in a highly hydrated polysaccharide matrix with interstitial voids in which nutrients and signaling molecules can be circulated. The structural and functional heterogeneity of bacterial cells within these communities protects them against the body’s natural defenses and provides them with antimicrobial resistance. Through genetic alterations, bacteria in bioﬁlms are also able to transition to the mobile planktonic form, which has been the traditional model for studying bacterial diseases (65,66). Bacterial bioﬁlms have been demonstrated on many areas of mucosa in the human body, including the ear mucosa and tympanostomy tubes removed from patients with chronic effusions and infections (67,68). It has been hypothesized that bioﬁlms may play an important role in cases that are refractory to antibiotic therapy, and antibiotic resistance has been demonstrated to be up to 1000-fold greater in bacteria in the bioﬁlm form versus the planktonic form (66–70). Similarities between chronic otitis media and CRS exist. Both of these disease processes take place in the ciliated respiratory epithelium and are largely associated with an infectious etiology. The presence of bacterial bioﬁlms in CRS patients with culture-positive Pseudomonas has been demonstrated using scanning electron microscopy (71) (Fig. 7). Although further work in this area is required, knowledge of the presence, structural characteristics, and pathological mechanism of bioﬁlms in CRS may help to identify new treatment modalities. Superantigens. Another new area of interest in infectious CRS involves a group of potent mitogens termed superantigens sags. Sags are most commonly associated with bacteria, particularly S. aureus and S. pyogenes species, but can also be produced by viruses and fungi. Unlike conventional antigens whose activation requires multiple steps in only a limited number of T-lymphocytes, sags can directly stimulate a multitude of different T-lymphocytes. J Figure 7 (Facing page) Bioﬁlms in Human CRS. Source: Cyer J, Schipor I, Perloff JR, Palmer JN. Densely coated sinonasal epithelium with tower-like structures (white arrows) visible near the top edge of the specimen. Source: From Ref. 71.

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In the traditional pathway, the antigen is phagocytosized by an antigenpresenting cell (APC), degraded into numerous peptide fragments, which are then processed for cell surface display in conjunction with a major histocompatibility complex (MHC) II receptor. A compatible T-helper cell then recognizes this MHC II/peptide complex, and an inﬂammatory response is initiated. Sags are able to bypass these processing and presenting steps and bind directly to the outside surfaces of the HLA-DR alpha domain of MHC class II and V beta domain of the T-cell receptors (picture) (72–75). Through this mechanism, they are able to stimulate a massive expression of IL-2 at femtomolar concentrations (76). In turn, IL-2 stimulates the production of other cytokines such as TNF-a, IL-1, Il-8, and platelet activating factor (PAF), leading to an overwhelming inﬂammatory response. Additionally, sags also act as traditional antigens, as well as stimulate the production of antisuperantigen antibodies. Recently, upregulation of IgE sags antibodies have been demonstrated in patients with chronic obstructive pulmonary disease (COPD) exacerbation (77). Likewise, a study by Basher et al. found increased levels of sags in patients with NP versus control patients (78). Evidence of the roles of superantigen-producing bacterial strains in the pathologic mechanism of Kawasaki disease, atopic dermititis, and rheumatoid arthritis has also been reported, and a pathophysiological mechanism in which microbial persistence and superantigen-induced T-cell inﬂammatory responses in CRS has also been proposed (79). Further studies in this area, as well as in other areas of CRS, may provide new diagnostic and treatment modalities. Fungal infections: Fungal species play a variety of roles in chronic sinusitis from colonization to invasive, life-threatening disease. Invasive disease is characterized by histopathological evidence of hyphal forms within the sinus mucosa, submucosa, blood vessels, or bone, and has been associated with either fulminate or a more indolent chronic course of fungal rhinosinusitis. In addition, chronic invasive disease may or may not be associated with a giant cell response. The pathophysiology of these different disease courses has been attributed primarily to the host’s immune response to the fungus, although the fungal species also appears to play some role in the disease course. Fungal species associated with fulminate forms of fungal sinusitis include Absidia, Aspergillus, Basidobolus, Mucor, and Rhizopus spp., and most often occur in immunocompromised patients (80). Species associated with chronic invasive fungal sinusitis include Aspergillus, Mucor, Alternaria, Curvularia, Bipolaris, and Candida spp., Sporothrix schenckii, and Pseudallescheria boydii, and can occur in both immunocompetent and immunocompromised patients (81,82). Two major forms of non-invasive fungal sinusitis—allergic fungal sinusitis and sinus mycetoma—exist, with allergic fungal rhinosinusitis (AFS) forming a distinct subcategory of CRS. Diagnostic criteria for AFS

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Figure 8 Hematoxylin and eosin stained nasal tissue demonstrating fungal hyphae, eosinophils and Charcot-Leyden crystals. Source: Diagnosis of chronic rhinosinusitis. Lanza DC. Annals of Otology, Rhinology, & Laryngology – Supplement. 2004; 193:10–14.

include the demonstration of ﬁve characteristics as deﬁned by Bent and Kuhn: gross production of eosinophilic mucin containing non-invasive fungal hyphae, nasal polyposis, characteristic radiographic ﬁndings, immunocompetence, and allergy to fungus (83). AFS is characterized by a sustained eosinophilic inﬂammatory response to colonizing fungi. Mucus secretions, termed allergic mucin, in AFS are characterized as being highly viscous and contain branching non-invasive fungal hyphae within sheets of eosinophils and Charcot–Leyden crystals (84–88) (Fig. 8). A non-IgE-dependent association of fungus with CRS has also been proposed. In 1999, Ponikau et al. reported a fungal colonization in 96% of consecutive patients with CRS, using an ultra-sensitive method of fungal identiﬁcation. Additionally, certain fungi were demonstrated to elicit an upregulation of IL-5 and IL-13 and a resulting eosinophilic inﬂammatory response. This eosinophilic response was IgE, and therefore, allergy-independent, which was thought to indicate a broader role of fungus in CRS than previously hypothesized (89). Allergy Environmental allergens are frequently considered as important environmental factors in CRS, and atopy is identiﬁed as a prominent systemic host factor in CRS. However, the exact contribution of allergy to the development of CRS is still under investigation. Both pediatric and adult patients with allergic

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rhinitis are more commonly affected with CRS than non-allergic patients (90). Furthermore, these individuals have been reported to respond more poorly to medical management and to more frequently undergo endoscopic sinus surgery (91,92). Inﬂammatory changes contribute to the development of CRS in allergic patients. They are stimulated by the production of cytokines, allergic mediators, and neurogenic stimulation. More speciﬁcally, allergen stimulation of TH2 cells leads to the production of IL-4, which in turn causes B-cell activation and IgE antibody production. Subsequent allergen exposure causes IgE cross-linking and release of inﬂammatory mediators, such as histamine, leukotrienes, and tryptase, and results in the later phase response– eosinophil inﬁltration, mucus hypersecretion, and mucosal edema. Continued allergen activation, referred to as ‘‘priming,’’ further increases the concentration and magnitude of action of inﬂammatory cells such as eosinophils and neutrophils and their associated cytokines. Furthermore, an IgE response to staphylococcal antigens has been implicated in the development of NPs in CRS, and this relationship is currently under investigation (8,12,93–95). Environmental Pollutants A number of other environmental factors can be linked to the development of CRS. In a study of 5300 Swedish children, Andrae et al. found a signiﬁcantly higher rate of asthma and hay fever in children living near polluting factories (96). Futhermore, Suonpaa reported an increased incidence of acute sinusitis and nasal polyposis in southwestern Finland over a decade, which provides additional evidence for the presence of an environmental impact in CRS (97). Dust, ozone, sulfur dioxide, volatile organic compounds, and smoke are just a few of the pollutants that have been implicated in CRS. The majority of these chemicals share a similar pathologic mechanism: they act as nasal irritants causing dryness and local inﬂammation with an inﬂux of neutrophils (98,99). In addition to this mechanism, environmental tobacco smoke has been shown to cause secondary ciliary disorders, which consist primarily of microtubular defects (100). Occupational exposure to nickel, leather, or wood dust has been associated with epithelial metaplasia as well as carcinoma (101). SUMMARY Maintenance of key functional components—ostiomeatal patency, mucociliary clearance, and normal mucus production—of the paranasal sinus is essential for prevention and recovery from CRS. CRS is a complex disease process that can result from a single or multiple independent etiologies, as well as from multiple independent or interdependent etiologies (Fig. 9). The factors contributing to this disease process can be divided into systemic host, local host, and environmental factors. Systemic host factors, such as genetic and autoimmune diseases, are important to identify so that appropriate treatment modiﬁcations can be made, if available. Likewise,

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Figure 9 Etiological factors in the pathological cycle of CRS.

local host factors such as anatomic abnormalities and environmental factors such as infection, allergy, and pollution need to be recognized and appropriately managed. There is a clear need for further research into the pathophysiology of this disorder. Current research on bioﬁlms, sags, and osteitis will hopefully provide us with a better understanding of the role of infection in CRS. Likewise, research on allergic CRS and other noninfectious etiologies of CRS will help to better elucidate the role inﬂammation plays in this disorder. A better understanding of both infectious and inﬂammatory mechanisms of CRS will provide us with more effective and individualized therapies. REFERENCES 1. Majima, Y. Mucoactive medication and airway disease. Paediatr Respir Rev 2002; 3:104–109. 2. Lehrer RI, Lichenstein AK, Ganz T. Defensins: antimicrobial and cytotoxic peptides of mammalian cells. Annu Rev Immunol 1993; 11:105–128. 3. Martin E, Ganz T, Lehrer RI. Defensins and other endogenous peptide antibiotics of vertebrates. J Leukoc Biol 1995; 58:128–136. 4. Lee SH, Kim JE, Lee HM, Choi JO. Antimicrobial defensin peptides of the human nasal mucosa. Ann Otol Rhino Laryngol 2002; 111(2):135–141. 5. Goldman MJ, Anderson GM, Stolzenberg ED, Kari UP, Zasloff M, Wilson JM. Human beta-defensin-1 is a salt sensitive antibiotic that is inactivated in cystic ﬁbrosis. Cell 1997; 88:553–560. 6. Knowles MR, Bouchers RC. Mucus clearance as a primary innate defense mechanism for mammalian airways. J Clin Investig 2002; 109:571–577.

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24. Nonoyama T, Harada T, Shinogi J, Yoshimura E, Sakakura Y. Immunohistochemical localization of cytokines and cell adhesion molecules in maxillary sinus mucosa in chronic sinusitis. Auris Nasis Larynx 2000; 27:51–58. 25. Bachert C, Wagemann M, Rudack C, Hopken KZ, Hillebrandt M, Wang D, van Cawenberge P. The role of cytokines in infectious sinusitis and nasal polyposis. Allergy 1998; 53:2–13. 26. Rudack C, Stoll W, Bachert C. Cytokines in nasal polyposis, acute and chronic sinusitis. Am J Rhinol 1998; 12:383–388. 27. Bachert C, Gevaert P, van Cauwenberge P. Staphylococcus aureus enterotoxins: a key in airway disease? Allergy 2002; 57:480–487. 28. Hamilos DL, Leung DY, Huston DP, Kamil A, Wood R, Hamid Q. GM-CSF, Il-5, and RANTES immunoreactivity and mRNA expression in chronic hyperplastic sinusitis with nasal polyposis. Clin Exp Allergy 1998; 28: 1145–1152. 29. Coste A, Girodon E, Louis S, Pruliere-Escabasse V, Goossens M, Peynegre R, Escudier E. Atypical sinusitis in adults must lead to looking for cystic ﬁbrosis and primary ciliary dyskinesia. Laryngoscope 2004; 144:839–843. 30. Varlotta L. Management and care of the newly diagnosed patient with cystic ﬁbrosis. Curr Opin Pulm Med 1998; 4:311–318. 31. Hulka GF. Head and neck manifestations of cystic ﬁbrosis and ciliary dyskinesia. Otolaryngol Clin North Am 2000; 33:1333–1341. 32. Doull JM. Recent advances in cystic ﬁbrosis. Arch Dis Child 2001; 85:62–66. 33. Gysin C, Alothman GA, Papsin BC. Sinonasal disease in cystic ﬁbrosis: clinical characteristics, diagnosis, and management. Pediatr Pulmonol 2000; 30:481–489. 34. Tandon R, Derkay C. Contemporary management of rhinosinusitis and cystic ﬁbrosis. Curr Opin Otolaryngol Head Neck Surg. 2003; 11:41–44. 35. Thaler ER. Postoperative care after endoscopic sinus surgery. Arch Otolaryngol Head Neck Surg 2002; 128:1204–1206. 36. Meeks M, Bush A. Primary ciliary dyskinesia. Pediatr Pulm 2000; 29:307–316. 37. Bianchi E, Savasta S, Carligaro A, Belufﬁ G, Poggi P, Tinelli M, Mevio E, Martinetti M. HLA haptlotype segregation and ultrastructure study in familial immotile cilia syndrome. Hum Genet 1992; 89:270–274. 38. Pan Y, McCaskill CD, Thompson K, Hicks J, Casey B, Shaffer LG, Craigen WJ. Paternal isodisomy of chromosome 7 associated with complete situs inversus and immotile cilia. Am J Hum Genet 1998; 62:1551–1555. 39. Witt M, Wang Y-F, Wang S, Sun C-E, Pawlik J, Rutkiewicz E, Zebrak J, Diehl SR. Exclusion of chromosome 7 for Kartenger syndrome but suggestion of linkage in families with other forms of primary ciliary dyskinesia. Am J Hum Genet 1998; 64:313–318. 40. Berlinger NT. Sinusitis in immunodeﬁcient and immunosuppressed patients. Laryngoscope 1985; 95:29–33. 41. Rubin J, Honigsberg R. Sinusitis in patients with acquired immunodeﬁciency syndrome. Ear Nose Throat J 1990; 69:460–463. 42. Friedman M, Landsberg R, Tanyeri H, Schults RA, Kelanic S, Caldarelli DD. Endoscopic sinus surgery in patients with HIV. Laryngoscope 2000; 110: 1613–1616.

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43. Long CM, Smith TL, Loehrl TA, Komorowski RA, Tookill TJ. Sinonasal disease in patients with sarcoidosis. Am J Rhinol 2001; 15:211–215. 44. Hewins P, Tervaert JW, Savage CO, Kallenberg CG. Is Wegner’s granulomatosis and autoimmune disease? Curr Opin Rheumatol 2000; 12:3–10. 45. Watts RA. Wegener’s granulomatosis: unusual presentations. Hosp Med 2000; 61:250–253. 46. Settipane RA, Lieberman P. Update on nonallergic rhinitis. Ann Allergy Asthma Immunol 2001; 86:494–507. 47. Beers RF. Intolerance to aspirin. Ann Intern Med 1968; 68:975–983. 48. Jones NS. CT of paranasal sinuses: a review of the correlation with clinical, surgical, and histopathologic ﬁndings. Clin Otolaryngol 2002; 27:11–17. 49. Alho OP. Paranasal sinus bony structures and sinus functioning during viral colds in subjects with and without a history of recurrent sinusitis. Laryngoscope 2003; 113:2163–2168. 50. Richtsmeier WJ. Top 10 reasons for endoscopic maxillary sinus surgery failure. Laryngoscope 2001; 111:1952–1956. 51. Som PM, Shapiro MD, Biller HF, Sasaki C, Lawson W. Sinonasal tumors and inﬂammatory tissue differentiation with MR imaging. Radiology 1988; 167: 803–808. 52. Naranch K, Park YJ, Repka-Ramirez MS, Velarde A, Clauw D, Baranick JN. A tender sinus does not always mean rhinosinusitis. Otolaryngol Head Neck Surg 2002; 127:387–397. 53. Kennedy DW, Senior BA, Gannon FH, Montone KT, Hwang P, Lanza DC. Histology and histomorpholometry of ethmoid bone in chronic rhinosinusitis. Laryngoscope 1998; 108:502–507. 54. Perloff JR, Gannon FH, Bolger WE, Montone KT, Orlandi R, Kennedy DW. Bone involvement in sinusitis: an apparent pathway for the spread of disease. Laryngoscope 2000; 110:2095–2099. 55. Khalid AN, Hunt J, Perloff JR, Kennedy DW. The role of bone in chronic sinusitis. Laryngoscope 2002; 112(11):1951–1957. 56. Brook I. Sinusitis—overcoming bacterial resistance. Int J Pediatr Otorhinolaryngol 2001; 58:27–36. 57. Brook I, Yoeum P, Shah K. Aerobic and anaerobic bacteriology of concurrent chronic otitis media with effusion and chronic sinusitis. Arch Otolaryngol Head Neck Surg 2000; 126:174–176. 58. Doyle PW, Woodham JD. Evaluation of the microbiology of chronic ethmoid sinusitis. J Clin Microbiol 1991; 29:2396–2400. 59. Hoyt WH III. Bacterial patterns found in patients with chronic sinusitis. J Am Osteopath Assoc 1992; 92:209–212. 60. Hsu J, Lanza, DC, Kennedy DW. Antimicrobial resistance in bacterial chronic sinusitis. Am J Rhinol 1998; 12:243–248. 61. Biel MA, Brown CA, Levinson RM, Gavis GE, Paisner HM, Sigel ME, Tedford TM. Evaluation of the microbiology of chronic maxillary sinusitis. Ann Otol Rhinol Laryngol 1998: 107:942–945. 62. Brook I, Frazier EH. Correlation between microbiology and previous sinus surgery in patients with chronic maxillary sinusitis. Ann Otol Rhinol Laryngol 2001; 110:148–151.

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63. Jiang RS, Lin JF, Hsu CY. Correlation between bacteriology of the middle meatus and ethmoid sinus in chronic sinusitis. J Laryngol Otol 2002; 116:443–446. 64. Finegold SM, Flynn MJ, Rose FV, et al. Bacteriologic ﬁndings associated with chronic bacterial maxillary sinusitis in adults. Clin Infect Dis 2002; 35:428–433. 65. Costerton JW, Vech R, Shirtlift M, Pasmore M, Post JC, Erlich G. The application of bioﬁlm science to the study and control of chronic bacterial infections. J Clin Invest 2003; 112:1446–1477. 66. Stewart PS, Costerton JW. Antibiotic resistance of bacterial bioﬁlms. Lancet 2001; 358:135–138. 67. Post CJ. Direct evidence of bacterial bioﬁlms in otitis media. Laryngoscope 2001; 111(12):2083–2094. 68. Ehrlich GD, Vech R, Wang X, Costerton JW, Hayes JD, Hu FZ, Daigle BJ, Erlich MD, Post JC. Mucosal bioﬁlm formation on middle-ear mucosa in the chinchilla model of otitis media. JAMA 2002; 287:1710–1715. 69. Costerton JW, Stewart PS, Greenberg EP. Bacterial bioﬁlms: a common cause of persistent infections. Science 284:318–322. 70. Hoyle BD, Costerton WJ. Bacterial resistance to antibiotics: the role of bioﬁlms. Prog Drug Res 1991; 37:91–105. 71. Cryer J, Schipor I, Perloff JR, Palmer JN. Evidence of bacterial bioﬁlms in human chronic sinusitis. ORL 2004; 66:155–158. 72. Choi YW, Kotzin B, Heron L, Callahan J, Marrack P, Kappler J. Interaction of Staphylococcus aureus toxin ‘‘superantigen’’ with human T cells. Proc Natl Acad Sci USA 1989; 86:8941–8945. 73. Kappler J, Kotzin B, Herron L, Gelfand EW, Bigler RD, Boylston A, Carrel S, Posnett DN, Choi Y, Marrack P. V beta-speciﬁc stimulation of human T cells by staphylococcal toxins. Science 1989; 244:811–813. 74. Fraser JD. High-afﬁnity binding of staphylococcal enterotoxin A activated human T cells. J Immunol 1989; 144:4663–4669. 75. Hong-Geller H, Gupta G. Therapeutic approaches to superantigen-based diseases: a review. J Mol Recogn 2003; 16:91–101. 76. Carlsson R, Sjogren HO. Kinetics of IL-2 and interferon-gamma production, expression of IL-2 receptors, and cell proliferation in human mononuclear cells exposed to staphylococcal entertoxin A. Cell Immunol 1985; 96:175–183. 77. Rodhe G, Gevaert P, Holtappels G, Borg I, Wiethege A, Arinir U, SchultzeWerninghaus G, Bachert C. Increased IgE-antibodies to Staphylococcus aureus enterotoxins in patients with COPD. Respir Med 2004; 98:858–864. 78. Bachert C, Gevart P, Holtappels G, Johansson SG, van Crauwenberge P. Total and speciﬁc IgE in nasal polyps is related to local eosinophilic inﬂammation. J Allergy Clin Immunol 2001; 107:607–614. 79. Schubet MS. A superantigen hypothesis for the pathogenesis of chronic hypertrophic rhinosinusitis, allergic fungal sinusitis, and related disorders. Ann Allergy Asthma Immunol 2001; 87:181–188. 80. deShazo RD, O’Brien M, Chapin K, Soto-Aguilar M, Gardner L, Swain R. A new classiﬁcation and diagnostic criteria for invasive fungal sinusitis. Arch Otolaryngol Head Neck Surg 1997; 123:1181–1188. 81. Schell WA. Unusual fungal pathogens in fungal rhinosinusitis. Otolaryngol Clin North Am 2000; 33:375–387.

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82. Stringer S, Ryan MW. Chronic invasive fungal rhinosinusitis. Otolaryngol Clin North Am 2000; 33:375–387. 83. Bent JP III, Kuhn FA. Diagnosis of allergic fungal sinusitis. Otolaryngol Head Neck Surg 1994; 111:580–588. 84. Miloshev B, Davidson CM, Gentles JC, Sandison AT. Aspergilloma of paranasal sinuses and orbit in Northern Sudanese. Lancet 1966; 1:746–747. 85. Stevenson DD, Simon RA, Mathison DA, Christiansen SC Monteleukast is only partially effective in inhibiting aspirin responses in aspirin-sensitive asthmatics. Ann Allergy Asthma Immunol 2000; 85:477–482. 86. Miller J, Johnston A, Lamb D. Allergic aspergillosis of the maxillary sinuses. Proc Scot Thor Soc 1981; 36:710–715. 87. Lamb D, Miller J, Johnston A. Allergic aspergillosis of the paranasal sinuses. J Pathol 1982; 137. 88. Katzenstein AL, Sale SR, Greenberger PA. Allergic aspergillosis sinusitis: a newly recognized form of sinusitis. J Allergy Clin Immunol 1983; 72:89–93. 89. Ponikau JU, Sherris DA, Kern EB, et al. The diagnosis and incidence of allergic fungal sinusitis (AFS). Mayo Clin Proc 1999; 74:877–884. 90. Smith LF, Brindley PC. Indications, evaluation, complications, and results of functional endoscopic sinus surgery in 200 patients. Otolaryngol Head Neck Surg 1993; 108:688–696. 91. Benninger MS. Rhinitis, sinusitis and their relationship to allergy. Am J Rhinol 1992; 6:37–43. 92. Emaneul I, Shah S. Chronic rhinosinusitis: allergy and sinus computed tomographic relationships. Otolaryngol Head Neck Surg 2000; 123:687–691. 93. Baroody FM, Suh SH, Naclerio RM. Total IgE serum levels correlate with sinus mucosal thickness on CT. J Allergy Clin Immunol 1997; 100:563–568. 94. Naclerio RM, deTineo ML, Baroody FM. Ragweed allergic rhinitis and the paranasal sinuses. A computed tomographic study. Arch Otolaryngol Head Neck Surg 1997; 123:193–196. 95. Suzuki M, Watanabe T, Suko T, Mogi G. Comparison of sinusitis with and without allergic rhinitis: characteristics of paranasal sinus effusion and mucosa. Am J Otolaryngol 1999; 20:143–150. 96. Andrae S, Axelson O, Bjorksten B, Fredriksson M, Kjellman NJ. Symptoms of bronchial hyperreactivity and asthma in relation to environmental factors. Arch Dis Child 1988; 63:473–478. 97. Suonpaa J, Antila J. Increase of acute frontal sinusitis in southwestern Finland. Scand J Infect Dis 1990; 22:563–568. 98. Bascom R. Air pollution. In: Mygind N, Naclerio RM, eds. Allergic and Nonallergic Rhinitis. Copenhagen: Munksgaard, 1993:33–86. 99. Graham D, Henderson F, House D. Neutrophil inﬂux measured in nasal lavages of humans exposed to ozone. Arch Environ Health 1988; 43:228–233. 100. Afzlius B. Immotile cilia syndrome and ciliary abnormalities induced by infection and injury. Am Rev Respir Dis 1981; 124:107–109. 101. Zeiger RS. Differential diagnosis and classiﬁcation of rhinosinusitis. In: Schatz M, Zeiger RS, Settipane GA, eds. Nasal Manifestations of Systemic Diseases. Providence, RI: Oceanside Publications, 1991.

SECTION III. MICROBIOLOGY

7 Infective Basis of Acute and Recurrent Acute Sinusitis Ellen R. Wald Department of Pediatrics and Otolaryngology, University of Pittsburgh School of Medicine, Allergy, Immunology, and Infectious Diseases, Pittsburgh, Pennsylvania, U.S.A.

INTRODUCTION Sinusitis is a common complication of viral upper respiratory infection and allergic inﬂammation. Although the paranasal sinuses are believed to be sterile under normal circumstances, the upper respiratory tract—speciﬁcally the nose and nasopharynx—are heavily colonized by normal ﬂora. Despite differences in normal nasal ﬂora, the acute bacterial pathogens that cause acute sinusitis are similar in adults and children. OBTAINING SPECIMENS To determine the infective basis of acute or recurrent acute sinusitis, a sample of sinus secretions must be obtained from one of the paranasal sinuses without contamination by normal respiratory or oral ﬂora (1). The maxillary sinus is the most accessible of the paranasal sinuses. There are two non-endoscopic approaches to the maxillary sinus: via either the canine fossa or the inferior meatus. Both the canine fossa and the nasal vestibule are colonized by pathogenic bacteria. Accordingly, sterilization of the nasal vestibule and the mucosa beneath the inferior nasal turbinate or of the mucosa overlying the canine fossa is recommended if an aspirate of the maxillary sinus is planned. 135

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To avoid misinterpretation of culture results, acute infection is deﬁned as the recovery of a bacterial species in high density, that is, a colony count of at least 103–104 colony-forming units per milliliter (cfu/mL). This quantitative deﬁnition increases the probability that organisms recovered from the maxillary sinus aspirate truly represent in situ infection and not contamination from either the mucosa overlying the canine fossa or beneath the inferior turbinate. In fact, most sinus aspirates from acutely infected sinuses are associated with colony counts in excess of 104 cfu/mL. If quantitative cultures cannot be performed, Gram stain of the aspirated specimens affords semiquantitative data. If bacteria are readily apparent on a Gram stain, the approximate bacterial density is 105 cfu/mL. The Gram stain is especially helpful if bacteria are seen on the smear and the specimen fails to grow when using standard aerobic culture techniques. Anaerobic organisms or other fastidious bacteria, such as a bacterial bioﬁlm or partially antibiotic-treated infections, should be suspected. Performance of a Gram stain will also permit an assessment of the local inﬂammatory response. The presence of many white blood cells in association with a positive bacterial culture in high density makes it likely that a bacterial infection is present. Alternatively, a paucity or absence of white blood cells in association with the presence of a positive culture in low density suggests that these bacteria have contaminated the culture rather than have caused infection. Endoscopic Cultures in Children and Adults Recently there has been interest in and enthusiasm for obtaining cultures of the middle meatus endoscopically, as a surrogate for cultures of a sinus aspirate. The endoscopically obtained culture is less invasive and associated with less morbidity (2). In normal children, unfortunately, the middle meatus has been shown to be colonized by the same bacterial species such as Streptococcus pneumoniae, Haemophilus inﬂuenzae, and Moraxella catarrhalis, as are commonly recovered from children with sinus infection (3). Accordingly, middle meatus cultures are not interpretable. This technique cannot be recommended for a precise bacterial diagnosis in children with sinus infections. In three recent studies, cultures of the middle meatus have been obtained endoscopically from normal adults. The bacterial species recovered were coagulase-negative staphylococci in 35 to 50% of cultures, Corynebacterium spp. in 16 to 23% and Staphylococcus aureus in 8 to 20% (4–6). The only overlap between commensals and potential pathogens is S. aureus. While several studies in adults have shown a good correlation between cultures of the middle meatus and the sinus aspirate in patients with acute sinusitis (7,8), others have not (9,10). In a retrospective review of the literature between 1950 and 2000, Benninger et al. concluded that the data were insufﬁcient to recommend substitution of cultures of the middle meatus for maxillary sinus aspirates in patients with acute rhinosinusitis (11).

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Occasionally, neither a sinus aspirate nor a specimen obtained endoscopically is sufﬁcient for the diagnosis of a sinus infection. This is especially true of patients with very protracted symptoms. In this instance, biopsy of the sinus mucosa for culture and appropriate stains may be required. MICROBIOLOGY OF ACUTE SINUSITIS IN CHILDREN The microbiology of paranasal sinus infection can be anticipated according to the age of the patient, clinical presentation, and immunocompetency of the host. Despite the substantial prevalence and clinical importance of sinusitis in childhood, study of the microbiology of acute and subacute sinusitis in children has been relatively limited. Using a study design similar to the one described by investigators at the University of Virginia (12), an investigation of the microbiology of acute sinusitis in pediatric patients was reported by the Children’s Hospital of Pittsburgh in 1981 (13). Patients were eligible for this study if they were between 2 and 16 years of age and presented with one of two clinical pictures: onset with either ‘‘persistent’’ or ‘‘severe’’ respiratory symptoms. Sinus radiographs were performed on eligible children. When a maxillary sinus aspirate was performed on children presenting with clinical symptoms and signiﬁcantly abnormal sinus radiographs, bacteria in high density were recovered from 70% (14). The bacterial isolates in their relative order of prevalence are shown in Table 1. S. pneumoniae was most common, followed closely by H. inﬂuenzae and M. catarrhalis. No staphylococci were recovered. Mixed infection with heavy growth of two bacterial species was occasionally found. In 25% of patients with bilateral maxillary sinusitis, there were discordant bacterial culture results. In some cases, one sinus aspirate was positive, while the other was negative. In the remaining cases, different bacterial species were recovered from each aspirate. Table 1 Bacterial Species Cultured from 79 Sinus Aspirates in 50 Children

Streptococcus pneumoniae Moraxella catarrhalis Haemophilus inﬂuenzae Eikenella corrodens Group A streptococcus Group C streptococcus a-Streptococcus Peptostreptococcus Moraxella spp. Source: Adapted from Ref. 13.

Single isolates

Multiple isolates

Total

14 13 10 1 1 0 1 0 1

8 2 5 0 0 1 1 1 0

22 15 15 1 1 1 2 1 1

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Viral cultures were also performed on the maxillary sinus aspirates. Because many children were evaluated after 10 or more days of symptoms, viruses were recovered infrequently. Adenovirus as the only isolate was grown from the aspirate of one subject; parainﬂuenza virus in combination with a bacterial isolate was recovered from a second (13). In studies of adults with acute sinusitis, other viruses, including inﬂuenza and rhinovirus, have been recovered from approximately 10% of sinus aspirates (12). Nucleic acid ampliﬁcation technology was not available at the time of these investigations (12,13). MICROBIOLOGY OF ACUTE COMMUNITY-ACQUIRED SINUSITIS IN ADULTS Acute Maxillary Sinusitis The most elegant work detailing the microbiology of acute sinusitis has been done at the University of Virginia in Charlottesvile since 1975 (12). Information is derived mainly from cultures of specimens obtained by aspiration of the maxillary sinus because of the accessibility of this particular sinus. In general, a sinus infection is caused by a single bacterial isolate in high density. In 25% of cases, two bacterial species, each in high density, will be recovered. The two most important causes of acute community-acquired sinusitis in adults are S. pneumoniae and non-typeable H. inﬂuenzae (Table 2) (15,16). One remarkable change observed by Gwaltney et al. between 1975 and 1991 was the increase in the prevalence of beta-lactamase producing H. inﬂuenzae (16). Next in frequency were anaerobic bacterial species and streptococci other than pneumococci. The role of anaerobes in acute communityacquired disease has been variable. Although anaerobic bacteria have a more remarkable role in chronic rather than acute sinus disease, they account for 7% of acute cases, some of which arise from a primary dental pathology. Moraxella and S. aureus account for 4% and 3% of cases, respectively.

Table 2 Community-Acquired Acute Sinusitis in Adults Streptococcus pneumoniae Haemophilus inﬂuenzae Anaerobes Streptococcal species Moraxella catarrhalis Staphylococcus aureus Other Source: Adapted from Ref. 16.

41% 35% 7% 7% 4% 3% 4%

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Acute Sphenoid Sinusitis Most of the study of the microbiology of acute and recurrent acute sinusitis has focused on the maxillary sinus. There have been several reports on the microbiology of sphenoid sinusitis (17,18), including a recent study of 23 patients who were cared for between 1975 and 2000 (19). Most of the patients were adults. All of the specimens for culture were obtained at the time of surgery, suggesting that the population of patients studied had serious disease. The most common aerobic isolate in patients with acute disease was S. aureus. Streptococcal species (viridans streptococci, microaerophilic streptococci, S. pneumoniae, Group F streptococci, and Streptococcus pyogenes) were next most common. The predominance of gram-positive coccal species is consistent across all reports (17–19). There were two isolates of H. inﬂuenzae. Anaerobes were recovered from several patients (Peptostreptococcus spp., Propionibacterium acnes, Fusobacterium nucleatum, and Prevotella melaninogenica). Acute Frontal Sinusitis The microbiology of frontal sinusitis has been evaluated in three studies (20–22). In a recent review of Brook’s experience over a 26-year period, 28 cases of frontal sinusitis were described microbiologically (15 acute and 13 chronic) (22). The primary isolates in patients with acute frontal sinusitis were S. pneumoniae, H. inﬂuenzae, and M. catarrhalis. There was an occasional isolation of anaerobes. These results are similar to those described by other authors (22,21). Recurrent Acute Bacterial Sinusitis There has been relatively little study of the microbiology of recurrent acute sinusitis. One small series, recently published, reviewed the results for eight patients (23). Specimens were obtained via maxillary sinus endoscopy under local anesthesia, through the middle meatus, with calcium alginate–tipped microswabs. The swabs were placed in 1 mL of media and shaken vigorously for two minutes, serially diluted, and inoculated. Only bacteria found in numbers greater than 104/mL were considered to be pathogens. Not surprisingly, the isolates recovered were S. pneumoniae, H. inﬂuenzae, and M. catarrhalis. There was only a single isolate of S. aureus. Viruses as a Cause of Acute sinusitis Although we commonly consider acute sinusitis to be a complication of viral upper respiratory tract infections, several investigators have shown that radiographic and other imaging abnormalities are very common in both children and adults with the common cold, suggesting the presence of early viral sinusitis (24,25). In a study by Puhakka et al., 200 young adults with

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the common cold were followed for 21 days. Plain radiographs were performed on days 1, 7, and 21 of the common cold (26). Patients recorded their symptoms on a diary card for 20 days, rating symptoms such as watery rhinitis, purulent rhinitis, nasal congestion, nasal irritation, headache, cough, sputum, sore throat, and fever on a severity scale of zero to three (ranging from absent to severe). The etiologic role of 10 viruses (rhinovirus, adenovirus, coronavirus, enterovirus, inﬂuenza A and B viruses, parainﬂuenza virus types 1, 2, and 3, and respiratory syncytial virus) was investigated by virus culture, antigen detection, serology, and rhinovirus polymerase chain reaction (PCR). Antibody concentrations to ﬁve bacteria (Chlamydia pneumoniae, H. inﬂuenzae, M. catarrhalis, Mycoplasma pneumoniae and S. pneumoniae) were assayed. Altogether, 57% of the patients had sinus abnormalities (mucosal thickening, total opacity, air–ﬂuid level, cyst, or polyp) during the 21 days of the common cold. This compares to 87% of adult patients with an uncomplicated common cold demonstrating signiﬁcant abnormalities when evaluated by computed tomography (24). Antimicrobial treatment was not provided in this study and all patients recovered spontaneously, suggesting that there was no substantial component of bacterial superinfection (26). The etiology of the common cold was determined in 69.5% of the subjects. Viral infection was detected in 81.6% of the patients with sinusitis and in 63.3% of the patients without sinusitis. Rhinovirus was the most frequent cause of infection, detected in 55.3% and in 48.3% of subjects, respectively. No signiﬁcantly increased levels of antibodies to bacteria were detected in the sinusitis group. Support for the likelihood that these cases of radiologic ‘‘sinusitis’’ represent actual virus infection of the paranasal sinuses is found in a study by Pitkaranta et al. (27). Twenty adult patients with a diagnosis of acute community-acquired sinusitis were studied between May and July of 1996. All patients had purulent rhinorrhea, nasal obstruction, and abnormal radiographs. A nasal swab was obtained from each patient at the area of puncture below the inferior turbinate. After puncture with a needle, a bronchoscope brush was passed through the needle into the sinus and rotated. Cultures and PCR for virus were performed on the nasal swab and the bronchial brush specimen. Rhinovirus was detected in specimens from 10 of the patients, including maxillary samples from eight and nasal swabs from nine by reverse transcription–PCR (RT–PCR). These ﬁndings suggest that viral invasion of the sinus cavity itself may be a common event during uncomplicated upper respiratory infections. However, a positive PCR may also have been caused by the presence of virions in the sinus or viral RNA produced by replication elsewhere in the upper respiratory tract epithelium and introduced during coughing or sneezing, or potentially even by RNA from human rhinovirus introduced into the sinus at the time of puncture.

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Fungal Sinusitis Most cases of fungal sinusitis, especially the allergic forms of fungal sinusitis, present with very protracted clinical symptoms and therefore are not considered under the heading of either acute or recurrent acute sinusitis. The only type of fungal sinusitis likely to present as acute disease is locally or systemically invasive fungal sinusitis in immunoincompetent patients. Patients particularly prone to fungal infections of the paranasal sinuses include diabetics, patients with leukemia and solid malignancies who are febrile and neutropenic (most of whom will have received broadspectrum antimicrobial therapy), patients on high-dose steroid therapy (e.g., for connective tissue disease, transplant recipients), and patients with severe impairment of cell-mediated immunity (e.g., transplant recipients, persons with congenital T-cell immunodeﬁciencies) (28). The most common cause of fungal sinusitis in immunosuppressed patients is aspergillus. Much less commonly, acute or chronic sinusitis may be caused by Candida spp. or Mucor spp; the latter agent most frequently affects diabetic patients. In addition, Pseudallescheria boydii, Alternaria spp., Exserohilum spp., and Bipolaris spp. have been observed to cause sinusitis in the immunosuppressed. These infections will be covered in more detail in the chapters on sinusitis in the immunocompromised host and fungal sinusitis. Protozoa Although protozoan species have not been described as a cause of acute or chronic sinusitis in normal individuals, a case of acute sinusitis caused by cryptosporidium has been reported in a 17-year-old boy with congenital hypogammaglobulinemia, who presented with a three-week history of increasingly severe headaches (29). Physical examination showed turbid nasal discharge, friable nasal mucosa, and facial tenderness over the maxillary sinuses. CT revealed pansinusitis. The maxillary sinus aspirate contained a moderate number of neutrophils and rare Cryptosporidium oocysts. Extensive culturing for other microbiologic species was negative. The patient’s headache improved after therapy with oral spiramycin and intravenous 2 diﬂoro-methylornithine HCl-monohydrate.

CONCLUSION Most cases of clinically important acute and recurrent acute sinusitis are caused by the bacterial species S. pneumoniae, H. inﬂuenzae, and M. catarrhalis. The most common predisposing event is a viral upper respiratory tract infection. Coinfection by viruses and bacteria is likely, as is selflimited viral infection alone.

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REFERENCES 1. American Academy of Pediatrics. Subcommittee on Management of Sinusitis and Committee on Quality Improvement. Clinical practice guideline: management of sinusitis. Pediatrics 2001; 108:798–808. 2. Talbot GH, Kennedy DW, Scheld WM, Granito K. Rigid nasal endoscopy versus sinus puncture and aspiration for microbiologic documentation of acute bacterial maxillary sinusitis. Clin Infect Dis 2001; 33:1668–1675. 3. Gordts F, Abu Nasser I, Clement PA, Pierad D, Kaufman L. Bacteriology of the middle meatus in children. Int J Pediatr Otorhinolaryngol 1999; 48:163–167. 4. Gordts F, Harlewyck S, Pierard D, Kaufman L, Clement PA. Microbiology of the middle meatus: a comparison between normal adults and children. J Laryngol Otol 2000; 114:184–188. 5. Klossek JM, Dubreuil L, Richet H, Richet B, Sedallian A, Beutter P. Bacteriology of the adult middle meatus. J Laryngol Otol 1996; 110:847–849. 6. Nadel DM, Lanza DC, Kennedy DW. Endoscopically guided cultures in chronic sinusitis. Am J Rhinol 1998; 12:233–241. 7. Gold SM, Tami TA. Role of middle meatus aspiration culture in the diagnosis of chronic sinusitis. Laryngoscope 1997; 107:1586–1589. 8. Vogan JC, Bolger WE, Keyes AS. Endoscopically guided sinonasal cultures: a direct comparison with maxillary sinus aspirate cultures. Otolaryngol Head Neck Surg 2000; 122:370–373. 9. Winther B, Vicery CL, Gross CW, Hendley O. Microbiology of the maxillary sinus in adults with chronic sinus disease. Am J Rhinol 1996; 10:347–350. 10. Kountakis SE, Skoulas IG. Middle meatal vs. antral lavage cultures in intensive care unit patients. Otolaryngol Head Neck Surg 2002; 126:377–381. 11. Benninger MS, Appelbaum PC, Denneny JC, Osguthorpe DJ. Maxillary sinus puncture and culture in the diagnosis of acute rhinosinusitis: the case for pursuing alternative culture methods. Otolaryngol Head Neck Surg 2002; 127(1): 7–12. 12. Evans FO Jr, Sydnor JB, Moore WE, Moore GR, Manwaring JL, Brill AH, Jackson RT, Hanna S, Skaar JS, Holdeman LV, Fitz-Hugh S, Sande MA, Gwaltney JM Jr. Sinusitis of the maxillary antrum. N Engl J Med 1975; 293:735–739. 13. Wald ER, Milmoe GJ, Bowen AD, Ledesma-Medina J, Salmon N, Bluestone CD. Acute maxillary sinusitis in children. N Engl J Med 1981; 304: 749–754. 14. Wald ER, Reilly JS, Casselbrant M, Ledesma-Medina J, Milmoe GJ, Bluestone CD, Chiponis D. Treatment of acute maxillary sinusitis in childhood. A comparative study of amoxicillin and cefaclor. J Pediatr 1984; 104:297–302. 15. Anon JB, Jacobs MR, Poole MD, Ambrose PG, Benninger MS, Hadley JA, Craig WA. Sinus and allergy health partnership. Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Otolaryngol Head Neck Surg 2004; 130(suppl 1):1–45. 16. Gwaltney JM Jr. Acute community-acquired sinusitis. Clin Infect Dis 1996; 23:1209–1225. 17. Lew D, Southwick FS, Montgomery WW, Weber AL, Baker AS. Sphenoid sinusitis. A review of 30 cases. N Engl J Med 1983; 309:1149–1154.

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18. Ruoppi P, Seppa J, Pukkila M, Nuutinen J. Isolated sphenoid sinus diseases: report of 39 cases. Arch Otolaryngol Head Neck Surg 2000; 126:777–781. 19. Brook I. Bacteriology of acute and chronic sphenoid sinusitis. Ann Otol Rhinol Laryngol 2002; 111:1002–1004. 20. Suonpaa J, Antila J. Increase of acute frontal sinusitis in southwestern Finland. Scand J Infect Dis 1990; 22:563–568. 21. Ruoppi P, Seppa J, Nuutinen J. Acute frontal sinusitis: etiological factors and treatment outcome. Acta Otolaryngol (Stockh) 1993; 113:201–205. 22. Brook I. Bacteriology of acute and chronic frontal sinusitis. Arch Otolaryngol Head Neck Surg 2002; 128:583–585. 23. Brook I, Frazier EH. Microbiology of recurrent acute rhinosinusitis. Laryngoscope 2004; 114:129–131. 24. Gwaltney JM Jr, Phillips CG, Miller RD, Riker DK. Computed tomographic study of the common cold. N Engl J Med 1994; 330:25–30. 25. Glasier CM, Mallory GB Jr, Steele RW. Signiﬁcance of opaciﬁcation of the maxillary and ethmoid sinuses in infants. J Pediatr 1989; 114:45–50. 26. Puhakka T, Makela MJ, Alanen A, Kallio T, Korsoff L, Arstila P, Leinonen M, Pulkkinen M, Suonpaa J, Mertsola J, Ruuskanen O. Sinusitis in the common cold. J Allergy Clin Immunol 1998; 102:408. 27. Pitkaranta A, Arruda E, Molinberg H, Hayden FG. Detection of rhinovirus in sinus brushings of patients with acute community-acquired sinusitis by reverse transcription-PCR. J Clin Microbiol 1997; 35:1791–1793. 28. Wald ER. Microbiology of acute and chronic sinusitis in children and adults. Am J Med Sci 1998; 31:13–20. 29. Davis JJ, Heyman MB. Cryptosporidiosis and sinusitis in an immunodeﬁcient adolescent. J Infect Dis 1988; 158:649.

8 Infectious Causes of Sinusitis Itzhak Brook Departments of Pediatrics and Medicine, Georgetown University School of Medicine, Washington, D.C., U.S.A.

INTRODUCTION The upper respiratory tract, including the nasopharynx, serves as the reservoir for pathogenic bacteria that can cause respiratory infections including sinusitis (1). During a viral respiratory infection, potential pathogens can relocate from the nasopharynx to the sinus cavity, causing sinusitis (2). Establishment of the correct microbiology of all forms of sinusitis is of primary importance as it can serve as a guide for choosing adequate antimicrobial therapy. This chapter presents the current information regarding the microbiology of all forms of sinusitis. THE ORAL CAVITY NORMAL FLORA The human mucosal and epithelial surfaces are covered with aerobic and anaerobic microorganisms (3). The organisms that reside at these sites are predominantly anaerobic and are actively multiplying. The trachea, bronchi, esophagus, stomach, and upper urinary tract are not normally colonized by indigenous ﬂora. However, a limited number of transient organisms may be present at these sites from time to time. Microﬂora also vary in different sites within the body system, as in the oral cavity; the microorganisms present in the buccal folds differ in their concentration and types of strains from those isolated from the tongue or gingival sulci. However, the organisms that prevail in one body system tend to belong to certain major 145

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bacterial species, and their presence in that system is predictable. The relative and total counts of organisms can be affected by various factors, such as age, diet, anatomical variations, illness, hospitalization, and antimicrobial therapy. However, these sets of bacterial ﬂora, remain stable through life, with predictable patterns, despite their subjection to perturbing factors. Anaerobes outnumber aerobic bacteria in all mucosal surfaces, and certain organisms predominate in the different sites. The number of anaerobes at a site is generally inversely related to the oxygen tension (3). Their predominance in the skin, mouth, nose, and throat, which are exposed to oxygen, is explained by the anaerobic microenvironment generated by the facultative bacteria that consume oxygen. Knowledge of the composition of the ﬂora at certain sites is useful for predicting which organisms may be involved in an infection adjacent to that site and can assist in the selection of a logical antimicrobial therapy, even before the exact microbial etiology of the infection is known. The normal ﬂora is not just a potential hazard for the host, but also a beneﬁcial partner. Normal body ﬂora also serves as protector from colonization and subsequent invasion by potentially virulent bacteria. In instances where the host defenses are impaired or a breach occurs in the mucus membranes or skin, however, the members of the normal ﬂora can cause infections. Microbial Composition The formation of the normal oral ﬂora is initiated at birth. Certain organisms such as lactobacilli and anaerobic streptococci, which establish themselves at an early date, reach high numbers within a few days. Actinomyces, Fusobacterium, and Nocardia are acquired by the age of six months. Subsequently, Prevotella, Porphyromonas spp., Leptotrichia, Propionibacterium, and Candida also become part of the oral ﬂora (3). Fusobacterium populations attain high numbers after dentition and reach maximal numbers at age one year. The most predominant group of facultative microorganisms native to the oropharynx are the alpha-hemolytic streptococci, which include Streptococcus mitis, Streptococcus milleri, Streptococcus sanguis, Streptococcus intermedius, Streptococcus salivarius, and several others (4). Other groups of organisms native to the oropharynx are Moraxella catarrhalis and Haemophillus inﬂuenzae that are capable of producing beta-lactamase and may spread to adjacent sites causing otitis, sinusitis, or bronchitis. Encapsulated H. inﬂuenzae also induces serious infections such as meningitis and bacteremia. The oropharynx also contains Staphylococcus aureus and Staphylococcus epidermidis that can also produce beta-lactamase and take part in infections. The normal oropharynx is seldom colonized by gram-negative enterobacteriaceae. In contrast, hospitalized patients are generally heavily colonized with these organisms. The reasons for this change in microﬂora

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are not known, but may be related to changes in the glycocalyx of the pharyngeal epithelial cells or because of selective processes that occur following the administration of antimicrobial therapy (5). The shift from predominantly gram-positive to gram-negative bacteria is thought to contribute to the high incidence of sinus infection caused by gram-negative bacteria in patients with chronic illnesses. Anaerobic bacteria are present in large numbers in the oropharynx, particularly in patients with poor dental hygiene, caries, or periodontal disease. They outnumber their aerobic counterpart in a ratio of 10:1 to 100:1 (Fig. 1). Anaerobic bacteria can adhere to tooth surfaces and contribute, through the elaboration of metabolic by-products, to the development of both caries and periodontal disease (4). The predominant anaerobes are anaerobic streptococci, Veillonella spp., Bacteroides spp., pigmented Prevotella, and Porphyromonas spp. (previously called Bacteroides melaninogenicus group), and Fusobacterium spp. (4). These organisms are a potential source of a variety of chronic infections including otitis and sinusitis, aspiration pneumonia lung abscesses, and abscesses of the oropharynx and teeth. The microﬂora of the oral cavity is complex and contains many kinds of obligate anaerobes. The distribution of bacteria within the mouth seems to be a function of their ability to adhere to the oral surfaces. The differences in numbers of the anaerobic microﬂora probably occur because of considerable variations in the oxygen concentration in parts of the oral cavity.

Figure 1 Oropharyngeal ﬂora.

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For example, the maxillary and mandibular buccal folds contain 0.4% and 0.3% oxygen, respectively, whereas the anterior and posterior tongue surfaces contain 16.4% and 12.4%. The environment of the gingival sulcus is more anaerobic than the buccal folds, and the periodontal pocket is the most anaerobic area in the oral cavity. The ratio of anaerobic bacteria to aerobic bacteria in saliva is approximately 10:1. The total count of anaerobic bacteria is 1.1 108/mL (Fig. 1). The predominant anaerobic bacteria that colonize the anterior nose are P. acnes. Fusobacterium nucleatum is the main species of Fusobacterium present in the oral cavity. Anaerobic gram-negative bacilli found in the oral cavity include pigmented Prevotella and Porphyromonas (previously called black-pigmented Bacteroides), Porphyromonas gingivalis, Prevotella oralis, Prevotella orisbuccae (ruminicola), Prevotella disiens, and Bacteroides ureolyticus. Fusobacteria are also a predominant part of the oral ﬂora (6), as the treponemas (7). Pigmented Prevotella and Porphyromonas represent <1% of the coronal tooth surface, but constitute 4% to 8% of gingival crevice ﬂora. Veillonellae represent 1% to 3% of the coronal tooth surface, 5% to 15% of the gingival crevice ﬂora, and 10% to 15% of the tongue ﬂora. Microaerophilic streptococci predominate in all areas of the oral cavity, and they reach high numbers in the tongue and cheek (8). Other anaerobes prevalent in the mouth are Actinomyces (9), Peptostreptococci, Leptotrichia buccalis, Biﬁdobacterium, Eubacterium, and Propionibacterium (10). Pigmented Prevotella, Porphyromonas, and Fusobacterium species can also produce beta-lactamase (11). The recovery rate of aerobic and anaerobic beta-lactamase producing bacteria (BLPB) in the oropharynx has increased in recent years, and these organisms were isolated from more than half of the patients with head and neck infections including sinusitis (11). BLPB can be involved directly in the infection, protecting not only themselves from the activity of penicillins but also penicillin-susceptible organisms. This can occur when the enzyme beta-lactamase is secreted into the infected tissue or abscess ﬂuid in sufﬁcient quantities to break the penicillin’s beta-lactam ring before it can kill the susceptible bacteria (12) (Fig. 2). The high incidence of recovery of BLPB in upper respiratory tract infections may be because of the selection of these organisms following antimicrobial therapy with beta-lactam antibiotics. Emergence of penicillinresistant ﬂora can occur following only a short course of penicillin (13,14). Obtaining Appropriate Sinus Content Cultures while Avoiding the Normal Flora If a patient with sinusitis develops severe infection, is immunocompromised or fails to show signiﬁcant improvement or shows signs of deterioration despite treatment, it is important to obtain a culture, preferably through sinus puncture, as this may reveal the presence of causative bacteria.

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Figure 2 Protection of penicillin-susceptible bacteria from penicillin by betalactamase-producing bacteria.

However, obtaining a culture through sinus endoscopy is an alternative approach. Sinus aspirates for culture must be obtained free of contamination so that saprophytic organisms or normal ﬂora are excluded and culture results can be interpreted correctly. As indigenous aerobic and anaerobic bacteria are present on the nasopharyngeal mucous membranes in large numbers, even minimal contamination of a specimen with the normal ﬂora can give misleading results. The use of sinus puncture is the ‘‘gold standard’’ method of obtaining such specimens (15). There is, however, data that supports the use of endoscopically obtained cultures in assessing the microbiology of infected sinuses (16a–23). Sinus Puncture Obtaining sinus aspirates by puncture is the traditional method of specimens collection. The maxillary sinus is the most accessible of all of the paranasal sinuses. There are two approaches to the maxillary sinus that use puncture: via either the canine fossa or the inferior meatus. The nasal vestibule is often heavily colonized with pathogenic bacteria, mostly S. aureus. Therefore, sterilization of the nasal vestibule and the area beneath the inferior nasal turbinate is suggested. Contamination with nasal ﬂora may, however, occur. To prevent misinterpretation of the culture results, an infection is deﬁned as the recovery of a bacterial species in high density [i.e., a colony count of at least 103 to 104 colony forming units per milliliter (cfu/mL)]. This quantitative deﬁnition increases the probability that microorganisms isolated from the sinus aspirate truly represent in situ infection and not contamination. Most

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aspirates from infected sinuses contain colony counts above 104 cfu/mL. If quantitative cultures cannot be performed, Gram stain of aspirated specimens enables semiquantitative assessment. If bacteria are readily seen on a Gram stain preparation, the approximate bacterial density is about 105 cfu/mL. Of 12 cases in which an antral puncture showed at least 105 cfu/mL pathogens, the Gram stain demonstrated either organisms or white blood cells in all 12 cases, and organisms as well as white blood cells in 9 of 12 cases (16a). A Gram stain is especially useful if organisms are observed on smear and the specimen fails to grow using standard aerobic culture techniques, in which case anaerobic organisms or other fastidious bacteria or antibiotic-inhibited ﬂora should be suspected. A Gram stain can also allow an assessment of the local inﬂammatory response. The presence of many white blood cells in association with a positive bacterial culture in high density makes it probable that a bacterial infection is present. A Gram stain does not, however, differentiate between neutrophils and eosinophils. In contrast, a paucity or absence of white blood cells in association with the presence of a positive culture in low-density suggests bacterial contamination. Endoscopic Cultures Recently, there has been an interest in obtaining cultures of the middle meatus endoscopically, as a substitute or surrogate for cultures of a sinus aspirate. The endoscopically obtained culture is less invasive and associated with less morbidity (16a). Unfortunately, the middle meatus in normal children is colonized with the same bacterial species, namely, S. pneumoniae, H. inﬂuenzae, and M. catarrhalis, as are commonly recovered from children with sinus infection (17). Accordingly, this technique cannot be recommended for precise bacterial diagnosis in children with sinus infections. In three recent studies, the bacterial species recovered from middle meatal samples obtained from normal adults were coagulase-negative staphylococci (CNS, 35–50%), Corynebacterium spp. (16–23%), and S. aureus (8–20%) (18–20). The only overlap between commensals and potential pathogens is S. aureus. Several studies in adults have shown a good correlation between cultures of the middle meatus and the sinus aspirate in patients with acute sinusitis, especially when purulence is in the middle meatus (16a,21,22,25). However, other studies have not found such a correlation (23,24). Concordance in the types and concentrations of organisms recovered by endoscopic aspirates and those isolated during sinus surgery was found in all six cases in one study (25). Sixteen of the 18 anaerobes isolated from sinus aspirates were also found in the concomitant endoscopic sample. Five aerobic isolates were found in both sinus aspirates and endoscopic samples and their concentration was similar. However, contamination by four aerobic gram-positive bacteria (in numbers of <104 cfu/sample) were found in endoscopic samples.

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CNS is usually interpreted as a nonpathogen in acute sinusitis. Talbot et al. (16a) correlated the results of endoscopically obtained cultures and the cultures obtained from maxillary sinus aspirates. They reported no situations in which the puncture demonstrated CNS in >105 cfu/mL; however, a swab of the middle meatus grew CNS in 6 of 53 patients. Interpretation of the pathogenicity of S. aureus is more difﬁcult. Two of 53 patients had >105 cfu/mL, which correlated with the endoscopic swab. However, in an additional six patients, there was no agreement between sites (16a). In rare instances, neither a sinus aspirate nor a specimen obtained endoscopically is sufﬁcient for the diagnosis of a sinus infection. In this instance, biopsy of the sinus mucosa and broth culture and appropriate stains may be required to demonstrate the bacterial etiology. Discrepancies in the Recovery of Bacteria from Multiple Sinuses in Sinusitis There are differences in the distribution of organisms in a single patient who suffers from infections in multiple sinuses that emphasize the importance of obtaining cultures from all infected sinuses. A recent study has evaluated the discrepancies among infected sinuses by studying the aerobic and anaerobic microbiology of acute and chronic sinusitis in patients with involvement of multiple sinuses (16b). The 155 evaluated patients had sinusitis of either the maxillary, ethmoid, or frontal sinuses (any combination) and had organisms recovered from two to four concomitantly infected sinuses. Similar aerobic, facultative, and anaerobic organisms were recovered from all the groups of patients. In patients who had organisms isolated from two sinuses and had acute sinusitis, 31 (56%) of the 55 isolates were found only in a single sinus and 24 (44%) were recovered concomitantly from two sinuses. In those with chronic infection, 31 (34%) of the 91 isolates were recovered only from a single sinus and 60 (66%) were found concomitantly from two sinuses. Anaerobic bacteria were more often concomitantly isolated from two sinuses (50 of 70) than aerobic and facultative (10 of 21, p < 0.05). Similar ﬁndings were observed in patients who had organisms isolated from three or four sinuses. Beta-lactamase–producing bacteria were more often isolated from patients with chronic infection (58–83%) as compared to those with acute infections (32–43%). These ﬁndings illustrate that there are differences in the distribution of organisms in a single patient who suffers from infections in multiple sinuses, and emphasize the importance of obtaining cultures from all infected sinuses. INTERFERING FLORA The nasopharynx of healthy individuals is generally colonized by relatively nonpathogenic aerobic and anaerobic organisms (26), some of which

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Figure 3 The role of normal ﬂora in preventing colonization and subsequent infection by pathogenic bacteria.

possess the ability to interfere with the growth of potential pathogens (27) (Fig. 3). This phenomenon is called ‘‘bacterial interference.’’ These organisms include the aerobic alpha-hemolytic streptococci (mostly S. mitis and S. sanguis) (28) and anaerobic bacteria (Prevotella melaninogenica and Peptostreptococcus anaerobius) (29). Many of these organisms produce bacteriocins, which are bactericidal proteins. Nasopharyngeal carriage of upper respiratory tract pathogens such as S. pneumoniae, H. inﬂuenzae and M. catarrhalis can, however, occur in healthy individuals, and increases signiﬁcantly in the general population of young children during respiratory illness (30,31). The number of interfering organisms is lower in children prone to sinusitis (32). The absence of these organisms may explain the higher recovery of pathogens in these children. The presence of organisms with interfering potential may play a role in the prevention of colonization by pathogens and the occurrence of upper respiratory infections. Administration of antimicrobial agents can inﬂuence the composition of nasopharyngeal ﬂora (33). Members of the oral ﬂora with interfering capability (e.g., aerobic and anaerobic streptococci as well as penicillinsusceptible P. melaninogenica strains) can become resistant to amoxicillin, but stay susceptible to amoxicillin–clavulanate. Beta-lactamase–producing P. melaninogenica strains are susceptible to amoxicillin–clavulanate. All these organisms are more resistant to second- and third-generation cephalosporin therapy. Therapy with oral second-generation cephalosporins does not eliminate organisms with interfering capabilities, as do amoxicillin (34) or amoxicillin–clavulanate.

NASAL FLORA The origin of organisms that are introduced into the sinuses and may eventually cause sinusitis is the nasal cavity. The normal ﬂora of that site is comprised of certain bacterial species, which include S. aureus,

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S. epidermidis, alpha- and gamma-streptococci, Propionibacterium acnes, and aerobic diphtheroid (35–37). Potential sinus pathogens have been isolated from healthy nasal cavity but relatively rarely. These included S. pneumoniae (0.5–15%), H. inﬂuenzae (0–6%), M. catarrhalis (0–4%), Streptococcus pyogenes (0–1%), and anaerobic bacteria [Peptostreptococcus spp. (7–16%) and Prevotella spp. (6–8%)] (35–37). The ﬂora of the nasal cavity of patients with sinusitis is different from healthy ﬂora. While the recovery of Staphylococcus spp. and diphtheroids is reduced, the isolation of pathogens increases—S. pneumoniae was found in 36% of patients, H. inﬂuenzae in over 50%, S. pyogenes in 6%, and M. catarrhalis in 4% (38–42). In many studies of the nasal bacterial ﬂora in sinusitis, a simultaneous sinus aspirate was not taken (40,41), whereas in other studies, the correlation was found to be poor in some (40,43) but good in others (42,44). A good correlation was, however, found in one study (38); in this study, when the sinus aspirate culture yielded a presumed sinus pathogen, the same organism was found in the nasal cavity sample in 91% of the 185 patients. The predictive value of a pathogen-positive nasal ﬁnding was high for S. pyogenes (94%), H. inﬂuenzae (78%), and S. pneumoniae (69%), but was low for M. catarrhalis (20%). Despite this encouraging data, nasopharyngeal culture is not an acceptable alternative to culture through aspiration. NORMAL SINUS FLORA It is known that after sinus surgery, the sinus cavities quickly become colonized with bacteria and are no longer sterile. The question of whether normal bacterial ﬂora in the sinuses exists is controversial. The communication of the sinuses with the nasal cavity through the ostia could enable organisms that reside in the nasopharynx to spread into the sinus. Following closure of the ostium, these bacteria may become involved in the inﬂammation. Organisms have been recovered from uninﬂamed sinuses in several studies (45–48). The bacterial ﬂora of noninﬂamed sinuses was studied for aerobic and anaerobic bacteria in 12 adults who underwent corrective surgery for septal deviation (45). Organisms were recovered from all aspirates with an average of four isolates per sinus aspirate. The predominant anaerobic isolates were Prevotella, Porphyromonas, Fusobacterium, and Peptostreptococcus spp. The most common aerobic bacteria were S. pyogenes, S. aureus, S. pneumoniae, and H. inﬂuenzae. In another study, specimens were processed for aerobic bacteria only, and thus Staphylococcus spp. and alpha-hemolytic streptococci were isolated (46). Organisms were recovered in 20% of maxillary sinuses of patients who underwent surgical repositioning of the maxilla (47). In contrast, another report of aspirates of 12 volunteers with no sinus disease showed no bacterial growth (48). Jiang et al. evaluated (49) the bacteriology of maxillary

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sinuses with normal endoscopic ﬁndings. Organisms were recovered from 14 of 30 (47%) swab specimens and 7 of 17 (41%) of mucosal specimens. Gordts et al. (50) reported the microbiology of the middle meatus in normal adults. They noted in 52 patients that 75% had the presence of bacterial isolates, most commonly CNS (35%), Corynebacterium spp. (23%), and S. aureus (8%). However, only low numbers of these species were present as compared to previous studies in children where the most common organisms were H. inﬂuenzae (40%), M. catarrhalis (34%), and S. pneumoniae (50%) of children. Nonhemolytic streptococci and Moraxella spp. were absent in adults. MICROBIOLOGY OF SINUSITIS The pattern of many upper respiratory infections including sinusitis evolves through several phases (Fig. 4). The early stage often is a viral infection that generally lasts up to 10 days and complete recovery occurs in most individuals (39). However, in a small number of patients (estimated at 0.5%) with viral sinusitis, a secondary acute bacterial infection may develop. This is generally caused by facultative aerobic bacteria (i.e., S. pneumoniae, H. inﬂuenzae, and M. catarrhalis). If resolution does not take place, anaerobic bacteria of oral ﬂora origin become predominant over time. The dynamics of these bacterial changes were recently demonstrated by performing serial cultures in patients with maxillary sinusitis (51). The Role of Bacterial Superantigens in Sinus Disease Some microorganisms (bacteria, viruses, and fungi) can produce exotoxins (also called enterotoxins) that are able to nonspeciﬁcally up-regulate

Figure 4 Microbiological dynamics of sinusitis.

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T lymphocytes by cross-linking the MHC II molecule on antigen-presenting cells with the variable beta (Vb) region of the T-cell receptor (TCR). These exotoxins are called superantigens because they activate in a nonspeciﬁc manner the subpopulations representing up to 30% of T lymphocytes in contrast to classical antigens, which activate only <0.01% of T lymphocytes. Furthermore, superantigens can also act as classical antigens-bringing about the concomitant generation of antisuperantigen antibodies that are often IgE isotypes (52). S. aureus is a common colonizer of the nasal passage of patients with nasal polyps. S. aureus superantigens may play a role in nasal polyps, as 50% of polyp homogenates contained speciﬁc IgE to S. aureus exotoxins. Polyps associated with IgE to superantigens had signiﬁcantly greater eosinophilia and markers of eosinophilic inﬂammation than controls (53). Staphylococcal exotoxin-speciﬁc serum IgE was present in 5 of 10 (50%) patients with nasal polyposis and in none of 13 control patients. Patients with IgE to these superantigens have an increase in tissue eosinophilia and a higher incidence of asthma compared to control patients (54). S. aureus was present in 7 of 13 patients with nasal polyps and all produced exotoxins, namely, staphylococcus enterotoxin A (SEA), toxic shock syndrome toxin-1 (TSS T-1), or staphylococcus enterotoxin B (SEB). A clonal expansion of Vb speciﬁc to the isolated exotoxin was observed in the three patients studied (55). Viral Infections Viral illness is the most common predisposing factor for upper respiratory tract infections, including sinusitis (56). Rhino- and para-inﬂuenzae viruses are the most common causes of sinusitis (57,58). It is uncertain whether the viral infection precedes or is concurrent with the bacterial infection. The actual mechanisms by which a virus causes sinus disease are unknown. The mechanism whereby viruses predispose to sinusitis may involve microbial synergy, induction of local inﬂammation that blocks the sinus ostia, increase of bacterial attachment to the epithelial cells, and disruption of the local immune defense (Fig. 5). Epithelial cells are often infected with the common respiratory viruses, which can induce the production of several cytokines (56,59,60). In the case of rhinoviruses, the virus is transported to the posterior nasopharynx after deposition in the nose (59,61) and attaches to a speciﬁc rhinovirus receptor (62). Following initiation of the infection, several inﬂammatory pathways and the sympathetic nervous system, which generates the classic symptoms of a cold, are stimulated (63). The common cold involves not only the nasal passages but also the paranasal sinuses. Sinus computed tomography (CT) scans of 31 young adults with early common colds

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Figure 5 Dynamics of upper respiratory tract infection.

showed frequent abnormalities in the sinus cavity (64). Mucosal thickening is observed in radiographs of 87% of patients with colds (64), probably because of excess amounts of mucus discharged from goblet cells. These were observed in the maxillary, ethmoid, frontal, and sphenoid sinuses in 87, 65, 32, and 39% of the cases, respectively. Similar sinus abnormalities during colds were also observed in adults and children (65,66). Activation of the inﬂammatory pathways results in engorgement of the venous erectile tissue in the nasal turbinates, which leads to leakage of plasma into the nose and sinuses, discharge of goblet cells and seromucous glands, sneezing, and sensation of pain. CT scans show occlusion of the infundibulum in 77% of patients with viral rhinosinusitis (64). A malfunction in the ability of cilia to move material deposits towards the ostia because of the increased amount of viscous material and their induced slowing and paralysis is also observed (67). The adverse effect of this dysfunction is compounded by infundibular and osteomeatal obstruction from mucosal swelling. Some viral infections, such as inﬂuenza, can cause destructive epithelial damage, which enhances bacterial adherence. During a cold, nasal ﬂuid containing viruses, bacteria, and inﬂammatory mediators is suctioned into the sinus cavities where it produces inﬂammation and/or infection and is thickened by exocytosis of mucin from the numerous goblet cells in the sinus epithelium. The CT abnormalities observed in viral sinusitis could, therefore, be because of an inﬂammation alone or a viral infection of sinus epithelium cells. In sinus puncture studies in patients with acute community acquired rhinosinusitis, 15% of the sinus aspirates yielded rhinovirus, 5% inﬂuenza virus, 3% parainﬂuenza virus, and 2% adenovirus (68). Some of the sinus aspirates yielded both viruses and bacteria.

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Bacteria in Acute Sinusitis Bacteria can be isolated from two-thirds of patients with acute infection of the maxillary, ethmoid, frontal, and sphenoid sinuses (69). The microbiology of acute sinusitis is presented in greater details in Chapter 7. The bacteria recovered from pediatric and adult patients with community-acquired acute purulent sinusitis, using sinus aspiration by puncture or surgery, are the common respiratory pathogens (S. pneumoniae, M. catarrhalis, H. inﬂuenzae, and beta-hemolytic streptococci) and are considered as part of the normal ﬂora of the nose (S. aureus) (Table 1) (70–72). S. aureus is a common pathogen in sphenoid sinusitis (72), whereas the other organisms are common in other sinuses. The bacteria that cause the infection in children are generally the same as those found in acute otitis media. S. pneumoniae was isolated in 28% of 50 children with acute sinusitis, and both H. inﬂuenzae as well as M. catarrhalis were isolated in 19% of the aspirates. Beta-lactamase–producing strains of H. inﬂuenzae and M. catarrhalis were found in 20% and 27% of the cases, respectively. The infection is polymicrobial in about a third of the cases. Enteric bacteria are recovered less commonly, and anaerobes were recovered from only a few cases with acute sinusitis. However, appropriate methods for their recovery were rarely employed in most studies of acute sinusitis. Anaerobic bacteria are commonly recovered from acute sinusitis associated with dental disease, mostly as an extension of the infection from the roots of the premolar or molar teeth (73,74) (see Chap. 19). Pseudomonas aeruginosa and other gram-negative rods are common in sinusitis of nosocomial origin (especially in patients who have nasal tubes or catheters), the immunocompromised patients with human immunedeﬁciency virus (HIV) infection, and patients who suffer from cystic ﬁbrosis (75). Bacteria in Chronic Sinusitis Although the exact etiology of the inﬂammation associated with this chronic sinusitis is uncertain, the presence of bacteria within the sinuses in this patient population has been well documented (76,77). Most clinicians believe that bacteria play a major role in the etiology and pathogenesis of most cases of chronic sinusitis and prescribe antimicrobials therapy for its treatment. In contrast to the agreement regarding the microbiology of acute sinusitis, there is disagreement regarding the microbiology of chronic sinusitis. Unfortunately, there are several issues that confound the reliability of many of these studies and, therefore, contribute to the disparity of their results. These issues include: various methods used to sample the sinus cavity (i.e., aspiration, irrigation, Calginate swab, or biopsy); failure to sterilize the area

Source: From Refs. 16b, 68, 85, 90, 125–127.

Aerobic S. aureus S. pyogenes S. pneumoniae H. infuenzae M. catarrhalis Enterobactiaceae P. aeruginosa Anaerobic Peptostreptococccus sp. P. acnes Fusobacterium sp. Prevotella and Porphyromonas sp. B. fragilis

Bacteria

56 29 17 47 6

2 2 2

14 8 6 5 6 6 3

Chronic N ¼ 66

4 2 31 21 8 7 2

Acute

Maxillary

Table 1 Microbiology of Sinusitis (% of Patients)

15 12 4 8 –

15 8 35 27 8 – –

Acute N ¼ 26

59 18 47 82 –

24 6 6 6 – 47 6

Chronic N ¼ 17

Ethmoid

3 3 3 3 –

– 3 33 40 20 – –

Acute N ¼ 15

38 8 31 62 15

15 – – 15 – 8 8

Chronic N ¼ 13

Frontal

19 12 6 6 –

56 6 6 12 – – 6

Acute N ¼ 16

57 29 54 86 –

28 14

14 – – 14

Chronic N¼7

Splenoid

158 Brook

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through which the trocar or endoscope is passed; different sinuses or areas that are sampled (i.e., ethmoid bulla or maxillary antrum or middle meatus); lack of assessment of the inﬂammatory response; lack of quantitation of bacteria; previous or current use of antibiotics; variable patient selection (i.e., age, duration, extent of disease, surgical, or nonsurgical subjects), presence of nasal polyps and time of culture transport and method of culture. Numerous studies have examined the bacterial pathogens associated with chronic sinusitis. However, most of these studies did not employ methods that are adequate for the recovery of anaerobic bacteria. Studies have described signiﬁcant differences in the microbial pathogens present in chronic sinusitis as compared with acute sinusitis. S. aureus, S. epidermidis, and anaerobic gram-negative bacteria predominate in chronic sinusitis. The pathogenicity of some of the low virulence organisms such as S. epidermidis, a colonizer of the nasal cavity, is questionable (50,78). The absence of quantitation or performance of Gram stains in most studies prevents an assessment of both the density of organisms and the accompaniment of an inﬂammatory response. The common resistance of S. epidermidis to antimicrobials does not prove its pathogenicity. Although S. epidermidis is discounted as a pathogen in sinusitis, its role as a pathogen in other body sites has been well documented (i.e., neutropenic sepsis, infections of indwelling catheters, and in burn patients) (79). Their frequent recovery from swabs obtained from the middle meatus of normal subjects marks them as commensals and likely contaminants. In the unusual situation in which a large number of white blood cells and gram-positive cocci were present on Gram stain there was heavy growth of S. epidermidis, proper anaerobic cultures showed no growth of other organisms, and the possibility of a true infection by S. epidermidis should be entertained (80). Gram-negative enteric rods were also reported in recent studies (79–82). These included P. aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter spp., and Escherichia coli. As these organisms are rarely found in cultures of the middle meatus obtained from normal individuals, their isolation from these symptomatic patients may suggest their pathogenic role. These organisms may have been selected out following administration of antimicrobial therapy in patients with chronic sinusitis. The pathophysiology of chronic sinusitis often differs from that of acute sinusitis. The exact events leading to chronic sinusitis have been difﬁcult to identify or prove (83). It has been proposed that chronic sinusitis is an extension of unresolved acute sinusitis. As mentioned previously, the etiology of acute sinusitis frequently is viral, which can establish an environment that is synergistic with the growth of other organisms, both aerobic and anaerobic. If the infection is not properly treated, the inﬂammatory process can persist, which, over time, fosters the growth of anaerobic bacteria. Thus, the pathogens in sinusitis appear to evolve over the course of infection—from viruses to aerobic to anaerobic bacterial growth—as the

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symptoms and pathology persist over a period of weeks to months. (Figs. 4 and 5) The microbiology of chronic sinusitis differs from that of acute sinusitis (Table 1) (84–87). The transition from acute to chronic sinusitis by repeated aspiration of sinus secretions using endoscopy was illustrated in ﬁve patients who presented with acute maxillary sinusitis that did not respond to antimicrobial therapy (51). Most bacteria isolated from the ﬁrst culture were aerobic or facultative bacteria—S. pneumoniae, H. inﬂuenzae, and M. catarrhalis. Failure to respond to therapy was associated with the emergence of resistant aerobic and anaerobic bacteria in subsequent aspirates. These organisms included F. nucleatum, pigmented Prevotella, Porphyromonas spp., and Peptostreptococcus spp. (Fig. 6). Eradication of the infection was ﬁnally achieved by administration of effective antimicrobial agents and in three cases by surgical drainage. This study illustrates that as chronicity develops, the aerobic and facultative species are gradually replaced by anaerobes (51). This may result from the selective pressure of antimicrobial agents that enable resistant organisms to survive and from the development of conditions appropriate for anaerobic growth, which include the reduction in oxygen tension and an increase in acidity within the sinus (88). These are caused by the persistent edema and swelling, which reduce blood supply, and by the consumption of oxygen by the aerobic bacteria (88). Other factors are the emergence over time or selection of anaerobes that possess virulence factors such as capsule (89). In chronic infections, when adequate methods are used, anaerobes can be recovered in more than half of all cases; the usual pathogens in acute

Figure 6 Dynamics of sinusitis. Changes in the microbiology of sinusitis in 2 patients treated with antibiotics. Source: From Ref. 51.

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sinusitis (e.g., S. pneumoniae, H. inﬂuenzae, and M. catarrhalis) are found with lower frequency (84–87,90). Polymicrobial infection is common in chronic sinusitis, which is a synergistic infection (89) and may therefore be more difﬁcult to eradicate with narrow-spectrum antimicrobial agents. Chronic sinusitis caused by anaerobes is of particular concern, clinically, because many of the complications associated with this condition (e.g., mucocele formation, osteomyelitis, local and intracranial abscess) are caused by these organisms (91). That anaerobes play a role in chronic sinusitis is supported by the ability to induce chronic sinusitis in a rabbit by intrasinus inoculation of Bacteroides fragilis (92) and the rapid production of serum IgG antibodies against this organism in the infected animals (93). The pathogenic role of these organisms is also supported by the detection of antibodies (IgG) to two anaerobic organisms commonly recovered from sinus aspirates (F. nucleatum and P. intermedia) (94). Antibody levels to these organisms declined in the patients who responded to therapy and were cured, but not in those who failed therapy (Fig. 7). Aside from their role as pathogens, the production of beta-lactamases among many gram-negative anaerobes (e.g., Prevotella, Porphyromonas, and Fusobacterium spp.) can shield or protect other organisms, including aerobic pathogens, from beta-lactam antibiotics (12,95) (Fig. 2). Studies in Children There have been 10 studies of the microbiology of chronic rhinosinusitis in children between 1981 and 2000 (86,96–104). Four of these studies were

Figure 7 Serum antibodies to F. nucleatum and P. intermedia in 23 patients with chronic sinusitis. Source: From Ref. 94.

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prospective (96,97,101,103) and six were retrospective. In all but two studies, the maxillary sinus was sampled by transnasal aspiration. The most common criteria for evaluation were the symptoms that lasted over 90 days. An attempt was made to sterilize the nose prior to obtaining the culture only in ﬁve studies, and bacterial quantitation was rarely done. In two of the studies, normal nasal ﬂora (i.e., S. epidermidis and alpha-hemolytic streptococci) was recovered. It is difﬁcult to know what pathologic signiﬁcance to ascribe to these organisms. In the remaining studies, the usual sinus pathogens (i.e., H. inﬂuenzae, S. pneumoniae, and M. catarrhalis) were recovered in about 60% of cases. This was especially true when the criteria for entry included purulent secretions. In the remaining 30 to 40% of children, contaminants were recovered. Anaerobes were recovered in three studies, the only one that employed methods for their isolation (86,96,103). S. aureus (19%) and alpha-hemolytic streptococci (23%) were the predominant isolates in ethmoid sinusitis in one study (99), and S. epidermidis and alpha-hemolytic streptococci were the major ones in another (97). M. catarrhalis was the most common isolate in a study of children with allergies, although 25% of the patients had polymicrobial ﬂora (105). S. pneumoniae and H. inﬂuenzae predominated in children with acute exacerbations (106). Brook and Yocum (107) studied 40 children with chronic sinusitis. The sinuses infected were the maxillary (15 cases), ethmoid (13), and frontal (7). Pansinusitis was present in ﬁve patients. A total of 121 isolates (97 anaerobic and 24 aerobic) were recovered. Anaerobes were recovered from all 37 culture-positive specimens, and in 14 cases (38%) they were mixed with aerobes. The predominant anaerobic organisms were gram-negative bacilli (36 isolates), anaerobic gram-positive cocci (28), and Fusobacterium spp. (13). The predominant aerobic isolates were alpha-hemolytic streptococci (7), S. aureus (7), and Haemophilus spp. (4). Brook et al. (96) correlated the microbiology of concurrent chronic otitis media with effusion and chronic maxillary sinusitis in 32 children. Two-third of the patients had a bacterial etiology. The most common isolates were H. inﬂuenzae (9 isolates), S. pneumoniae (7), Prevotella spp. (8), and Peptostreptococcus spp. (6). Microbiological concordance between the ear and sinus was found in 22 (69%) of culture-positive patients. Erkan et al. (103) studied 93 chronically inﬂamed maxillary sinuses in children. Anaerobic bacteria were isolated in 81of 87 (93%) culture-positive specimens, recovered alone in 61 (70%) cases, and mixed with aerobic or facultative bacteria in 20 (23%). Aerobic or facultative bacteria were present alone in six cases (7%). A total of 261 isolates, 19 anaerobes, and 69 aerobes or facultatives were isolated. The predominant anaerobic organisms were Bacteroides spp. and anaerobic cocci; the predominant aerobes or facultatives were Streptococcus spp. and S. aureus.

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Studies in Adults The presence of anaerobic bacteria in chronic sinusitis in adults was found to be clinically signiﬁcant (108,109). In a study of chronic maxillary sinusitis Finegold et al. (87) found recurrence of signs and symptoms twice as frequent when cultures showed anaerobic bacterial counts above 103 cfu/mL. Anaerobes were identiﬁed in chronic sinusitis whenever techniques for their cultivation were employed. The predominant isolates were pigmented Prevotella, Fusobacterium, and Peptostreptococcus spp. The predominant aerobic bacteria were S. aureus, M. catarrhalis, and Haemophilus spp. Aerobic and anaerobic BLPB were isolated from over one-third of these patients (80,84,85,90,109,110). These BLPB were S. aureus, Haemophilus, Prevotella, Porphyromonas, and Fusobacterium spp. A summary of 17 studies of chronic sinusitis done since 1974, including 1758 patients (133 were children), is shown in Table 2 (85–87,103,110– 123). Anaerobes were recovered in 12% to 93% of patients. The variability in recovery may result from differences in the methodologies used for transportation and cultivation, patient population, geography, and previous antimicrobial therapy. Brook and Frazier (124), who correlated the microbiology with the history of sinus surgery in 108 patients with chronic maxillary sinusitis, found a higher rate of isolation of P. aeruginosa and other gram-negative bacilli in patients with previous sinus surgery. Anaerobes were, however, isolated more frequently in patients who did not have prior surgery. Brook et al. (125) evaluated the microbiology of 13 chronically infected frontal, seven sphenoid (126), and 17 ethmoid sinuses (127) (Table 1). Anaerobic bacteria were recovered in over two-thirds of the patients. The predominant anaerobes included Prevotella, Peptostreptococcus, and Fusobacterium spp. The main aerobic organisms were gram-negative bacilli (H. inﬂuenzae, K. pneumoniae, E. coli, and P. aeruginosa). Nadel et al. (80) also recovered gram-negative rods more commonly in previous surgery patients or those who had sinus irrigation. P. aeruginosa was more common in patients who received systemic steroids. Other studies have also noted this shift toward gram-negative organisms in patients who have been extensively and repeatedly treated (79,82,128a). The bacterial ﬂora includes Pseudomonas spp., Enterobacter spp., methicillin-resistant S. aureus, H. inﬂuenzae, and M. catarrhalis. Bacteria in Chronic Maxillary Sinusitis Associated with Nasal Polyposis Nasal polyps can impair paranasal sinus ventilation and drainage by blockage of the ostiomeatal complex. Several studies have shown that in the majority of cases of chronic sinusitis where nasal polyps are present, bacterial cultures are negative. Even polymerase chain reaction (PCR)

Abbreviation: NS, not speciﬁed.

Frederick and Braude (111) Van Cauwenberge et al. (112) Karma et al. (113) Berg et al. (114) Fiscella and Chow (115) Sedallian et al. (116) Simoncelli et al. (117) Tabaqchali (118) Brook (86) Hartog et al. (119) Ito et al. (120) Erkan et al. (103) Erkan et al. (121) Brook et al. (85) Edelstein et al. (122) Klossek et al. (123) Finegold et al. (87)

Ref. 83 66 40 adults 54 adults 15 adults 40 132 adults 35 40 children 90 10 93 children 126 adults 68 adults 114 adults 412 150 adults

No. of patients Chronic sinusitis Acute and chronic sinusitis Chronic sinusitis Chronic sinusitis Chronic sinusitis Chronic sinusitis Chronic sinusitis Chronic sinusitis Chronic sinusitis Chronic sinusitis Chronic maxillary sinusitis Chronic maxillary sinusitis Chronic maxillary sinusitis Chronic maxillary sinusitis Acute and chronic sinusitis Chronic sinusitis Chronic maxillary sinusitis

Condition 75 39 100 33 38 69 NS 70 100 81 100 93 90 100 NS NS 54

Patients from whom anaerobic organisms were isolated (%)

Table 2 Summary of 18 Studies on the Role of Anaerobes in Chronic Bacterial Sinusitis

52 39 19 42 48 46 22 39 80 29 60 93 88 82 12 26 49

Organisms that were anaerobes (%)

164 Brook

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techniques have failed to demonstrate bacterial infection in most cases (128b). Hamilos et al. (128c) obtained antral culture in 12 subjects with chronic maxillary sinusitis with nasal polyps and isolated organisms in only three patients. However, none of these studies employed methods that were adequate for the recovery of anaerobic bacteria. We evaluated aspirates of 48 chronically inﬂamed maxillary sinuses from patients who had nasal polyposis that were cultured for aerobic and anaerobic bacteria (128d). Bacterial growth was present in 46 (96%) specimens. Aerobic or facultative bacteria were present in 6 (13%) specimens, anaerobic bacteria alone in 18 (39%), and mixed aerobic and anaerobic bacteria in 22 (48%). There were 110 bacterial isolates (2.4 per specimen). Thirty-nine of the isolates were aerobic or facultative organisms (0.85 per specimen). The predominant aerobic or facultative organisms were S. aureus, microaerophilic streptococci, H. inﬂuenzae, and M. catarrhalis. There were 71 anaerobes isolated (1.5 per specimen). The predominant anaerobes were Peptostreptococcus spp., Prevotella spp., P. asaccharolytica, Fusobacterium spp., and P. acnes. These ﬁndings suggest that the microbiology of the maxillary sinus of patients with chronic sinusitis with polyposis is not different than those who develop chronic sinusitis without this condition, as the major isolates are polymicrobial aerobic–anaerobic ﬂora. Bacteria in Acute Exacerbation of Chronic Sinusitis Acute exacerbation of chronic sinusitis (AECS) represents a sudden worsening of the baseline chronic sinusitis with either worsening or new symptoms. Typically, the acute (not chronic) symptoms resolve completely between occurrences (129). We evaluated the microbiology of acute AECS (130) by performing repeated endoscopic sinus aspirations in seven patients over a period of 125 to 242 days. Bacteria were recovered from all 22 aspirates and the number of isolates varied between two and four. A total of 54 isolates were isolated, 16 aerobic as well as facultatives and 38 anaerobic bacteria. The aerobic bacteria were seven H. inﬂuenzae, three S. pneumoniae, three M. catarrhalis, two S. aureus, and one K. pneumoniae. The anaerobic bacteria included pigmented Prevotella and Porphyromonas spp. (19 isolates), Peptostreptococcus spp. (9), Fusobacterium spp. (8), and acnes (2). A change in the types of isolates was noted in all consecutive cultures obtained from the same patients as different organisms emerged and previously isolated bacteria were no longer recovered. An increase in antimicrobial resistance was noted in six instances. These ﬁndings illustrate the microbial dynamics of AECS where anaerobic and aerobic bacteria prevail and highlight the importance of obtaining cultures from patients with this infection for guidance in selection of proper antimicrobial therapy. Brook (131) compared the aerobic and anaerobic microbiology of maxillary AECS with the microbiology of chronic maxillary sinusitis.

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Included in the study were 32 cases with chronic sinusitis and 30 with AECS. A total of 81 isolates were recovered from the 32 cases (2.5 per specimen) with chronic sinusitis, 33 aerobic, and 48 anaerobic. Aerobes alone were recovered in eight specimens (25%), anaerobes only were isolated in 11 (34%), and mixed aerobes and anaerobes were recovered in 13 (41%). The predominant aerobic and facultatives were Enterobacteriacaeae and S. aureus. The predominant anaerobic bacteria were Peptostreptococcus spp., Fusobacterium spp., anaerobic gram-negative bacilli, and P. acnes. A total of 89 isolates were recovered from the 30 cases (3.0 per specimen) with AECS, 40 aerobic and facultatives, and 49 anaerobic. Aerobes were recovered in eight instances (27%), anaerobes only in 11 (37%), and mixed aerobes and anaerobes were recovered in 11 (37%). The predominant aerobes were S. pneumoniae, Enterobacteriaceae, and S. aureus. The prominante anaerobes were Peptostreptococcus spp., Fusobacterium spp., gram-negative bacilli, and P. acnes. This study illustrates that the organisms isolated from patients with AECS were predominantly anaerobic and were similar to those generally recovered in chronic sinusitis. However, aerobic bacteria that are usually found in acute infections (e.g., S. pneumoniae, H. inﬂuenzae, and M. catarrhalis) can also emerge in some of the episodes of AECS. Nosocomial Rhinosinusitis Patients with nosocomial sinusitis are usually those who require extended periods of intensive care (postoperative patients, burn victims, and patients with severe trauma) involving prolonged endotracheal or nasogastric intubation (132). Nasotracheal intubation places the patient at a substantially higher risk for nosocomial sinusitis than orotracheal intubation (133). Approximately 25% of patients requiring nasotracheal intubation for more than ﬁve days develop nosocomial sinusitis (134). In contrast to community-acquired sinusitis, the usual pathogens are gram-negative enterics (e,g., P. aeruginosa, K. pneumoniae, Enterobacter spp., P. mirabilis, and Serratia marcescens) and gram-positive cocci (occasionally streptococci and staphylococci) (chap. 16) (133–137). Whether these organisms are actually pathogenic is unclear, and they usually represent colonization of an environment with impaired mucociliary transport and foreign body presence in the nasal cavity. Evaluation of the microbiology of nosocomial sinusitis in nine children with neurologic impairment revealed anaerobic bacteria, always mixed with aerobic and facultative bacteria in 6 (67%) sinus aspirates and aerobic bacteria only in 3 (33%) (138). There were 24 bacterial isolates, 12 aerobic or facultative and 12 anaerobic. The predominant aerobic isolates were K. pneumoniae, E. coli, and S. aureus (two each) and P. mirabilis, P. aeruginosa, H. inﬂuenzae, M. catarrhalis, and S. pneumoniae (one each). The predominant anaerobes were Prevotella spp. (5), Peptostreptococcus

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spp. (4), F. nucleatum (2), and B. fragilis (1). Organisms similar to those recovered from the sinuses were also isolated from tracheostomy site and gastrostomy wound aspirates in ﬁve of seven instances. This study demonstrates the uniqueness of the microbiologic features of sinusitis in neurologically impaired children in which, in addition to the organisms known to cause infection in normal children, facultative and anaerobic gram-negative organisms that can colonize other body sites are predominant. Atypical Organisms Chlamydia pneumoniae has been isolated from patients with respiratory infection that included clinical features of sinusitis (139), and serological evidence of its presence in patients with sinusitis was found in only 2% of 103 patients (140). However, as it was only isolated in one case from sinus aspirate (141), its exact role in sinusitis is uncertain. Mycoplasma pneumoniae has been suspect as a cause of acute sinusitis, but no attempts have been made so far to recover it from infected sinuses. However, serological evidence of an increase in antibody titres suggests a link between sinusitis and M. pneumoniae infection (142) in purulent bacterial and nonpurulent nonbacterial sinusitis. One study identiﬁed M. pneumoniae–speciﬁc DNA in a small group of subjects with sinusitis and/or nasal polyposis (143). However, a more recent study failed to conﬁrm the presence of bacterial-speciﬁc DNA sequences for 16S ribosomal RNA (144). THE ROLE OF FUNGI IN SINUSITIS Fungal ‘‘colonization’’ of the nose and paranasal sinuses is common in the normal and inﬂamed sinuses because of the ubiquitous nature of the organisms (145–148). Under certain conditions, however, clinically signiﬁcant growth of fungus balls (also called mycetomas) or saprophytic growth of fungus may occur. This can cause the formation and accumulation of fungal mycelia within the nose and paranasal sinuses without signiﬁcant mucosal inﬂammation. In such cases, extirpation of the offending fungal growth is generally sufﬁcient. However, in other forms, the inﬂammatory response to the fungi may result in clinically signiﬁcant disease. Fungal sinusitis can be either noninvasive or invasive (chap. 20). Invasive involvement is generally considered as an acute and fulminant disease. In immunologically deﬁcient patients, however, the invasive fungal sinusitis is mild or not apparent, and can have a long and chronic course. Diagnosis is conﬁrmed by histological evidence of nasal or sinus invasive fungal involvement lasting longer than 12 weeks. Management of the disease necessitates correction of immunological deﬁciency, surgical debridements, and long-term systemic and topical

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antifungal treatment. The disease can progress and recur despite aggressive therapy, and can occasionally be fatal. Fungi can occasionally cause commonly acquired sinusitis (149). They are especially common in patients with uncontrolled diabetes, HIV disease, and those on prolonged immunosuppression therapy (especially transplant recipients) and courses of antimicrobial therapy. Aspergillus fumigatus is the most common fungus associated with sinusitis (150), and it can cause disease in normal as well as the immunocompromised hosts. The organism is a saprophyte of soil, dust, and decaying organic material. It has an invasive and a noninvasive form; its portal of entry is the respiratory tract. Sinusitis caused by aspergillus has been associated with the smoking of marijuana, as it contaminates the leaves. The organism has a noninvasive, an invasive, and a disseminated form. The noninvasive form causes chronic rhinitis and nasal obstruction, and if untreated, can spread to the blood stream, seeding numerous sites. Other Aspergillus species have also caused sinusitis in normal hosts and include Aspergillus ﬂavus and Aspergillus niger (151,152). Chronic invasive fungal sinusitis is divided into granulomatous and nongranulomatous subtypes based on histopathology. Chronic invasive fungal rhinosinusitis has been associated with Mucor, Alternaria, Curvularia, Bipolaris, Candida, Sporothrix schenckii, and Pseudallescheria boydii. Other fungi that can cause sinus infection include Schizophyllum commune (153), Emericella nidulans (154), Pseudoallescheria boydii (155), Paecilomyces spp., Cryptococcus neoformans, Penicillium melinii, Scedosporium (monosporium), Apiospermum, and Blastomycocis dermatitides (156). Saprophytic fungi causing infections are Oreschslera spp., Alternaria spp., Curvularia lunata, and Exserohilum spp. (157). Mucomycosis is caused by fungi of the Mucurales order. The sinusitis induced occurs mainly in diabetic and immunocompromised patients. Allergic sinusitis has been associated with Alternaria, Aspergillus, Bipolaris, Chrysporium, Dreschlera, and Exserohilum (158). Allergic fungal sinusitis from Aspergillus spp. is similar to allergic bronchopulmonary aspergillus with secretions containing eosinophils, Charcot–Leyden crystals, and fungal hyphe (159). Patients usually have evidence of atopy or asthma. The sinusitis is protracted and generally involves multiple sinuses. Myriodontium keratinophelum produces also allergic-like fungal sinusitis (160). The patients generally suffer from chronic sinusitis, nasal polyps, and proptosis owing to orbital and ethmoid cell invasion. Allergic fungal sinusitis was also described to be associated with Dreschslera (161), Alternaria, and Curvularia (162). Chronic invasive fungal sinusitis is divided into granulomatous and nongranulomatous subtypes based on histopathology. Chronic invasive fungal rhinosinusitis has been associated with Mucor, Alternaria, Curvularia, Bipolaris, Candida, S. schenckii, and P. boydii (152).

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CONCLUSION Sinusitis generally develops as a complication of viral or allergic inﬂammation of the upper respiratory tract. The bacterial pathogens in acute sinusitis are S. pneumoniae, H. inﬂuenzae, and M. catarrhalis, whereas anaerobic bacteria and S. aureus are predominant in chronic sinusitis. P. aeruginosa has emerged as a potential pathogen in the immunocompromised patients and in those who have nasal tubes or catheters, or are intubated.

REFERENCES 1. Faden H, Stanievich J, Brodsky L, Benstein J, Ogra PL. Changes in the nasopharyngeal ﬂora during otitis media of childhood. Pediatr Infect Dis 1990; 9:623–626. 2. Del Beccaro MA, Mendelman PM, Inglis AF, Richardson MA, Duncan NO, Clausen CR, Stull TL. Bacteriology of acute otitis media: a new perspective. J Pediatr 1992; 120:856–862. 3. Socransky SS, Manganiello SD. The oral microﬂora of man from birth to senility. J Periodontol 1971; 42:485–496. 4. Gibbons RJ, Socransky SS, Dearaujo WC, Varihoute J. Studies of the predominant cultivable microbiota of dental plaque. Arch Oral Biol 1964; 9: 365–370. 5. Valenti WM, Trudell RG, Bentley DW. Factors predisposing to oropharyngeal colonization with gram-negative bacilli in the aged. N Engl J Med 1978; 298:1108–1110. 6. Baird-Parker AC. The classiﬁcation of fusobacteria from the human mouth. J Genet Microbiol 1960; 22:458–469. 7. Smibert RM. Spirochaetales: a review. CRC Crit Rev Microbiol 1973; 2:491. 8. Gibbons RJ. Aspects of the pathogenicity and ecology of the indigenous oral ﬂora of man. In: Balows A, et al. eds. Anaerobic Bacteria, Role in Disease, Springﬁeld, IL: Charles C Thomas, 1974. 9. Rasmussen EG, Gibbons RJ, Socransky SS. A taxonomic study of ﬁfty grampositive anaerobic diphtheroides isolated from the oral cavity of man. Arch Oral Biol 1966; 11:573–579. 10. Gibbons RJ, Socransky SS, Sawyer S, Kapsimalii B, MacDonald JB. The microbiota of the gingival crevice of man: II. The predominant cultivable organisms. Arch Oral Biol 1963; 8:281–289. 11. Brook I. Beta-lactamase producing bacteria in head and neck infection. Larynscope 1988; 98:428–431. 12. Brook, I. The role of beta-lactamase-producing bacterial in the persistence of streptococcal tonsillar infection. Rev Infect Dis 1984; 6:601–607. 13. Brook I, Gober AE. Emergence of beta-lactamase-producing aerobic and anaerobic bacteria in the oropharynx of children following penicillin chemotherapy. Clin Pediatr 1984; 23:338–341.

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85. Brook I, Thompson D, Frazier E. Microbiology and management of chronic maxillary sinusitis. Arch Otolaryngol Head Neck Surg 1994; 120: 1317–1320. 86. Brook I. Bacteriologic features of chronic sinusitis in children. JAMA 1981; 246:967–969. 87. Finegold SM, Flynn MJ, Rose FV, Jousimies-Somer H, Jakielaszek C, McTeague M, Wexler HM, Berkowitz E, Wynne B. Bacteriologic ﬁndings associated with chronic bacterial maxillary sinusitis in adults. Clin Infect Dis 2002; 35:428–433. 88. Carenfelt C, Lundberg C. Purulent and non-purulent maxillary sinus secretions with respect to PO2, PCO2 and pH. Acta Otolaryngol 1977; 84:138–144. 89. Brook I. Role of encapsulated anaerobic bacteria in synergistic infections. Crit Rev Microbiol 1987; 14:171–193. 90. Brook I. Bacteriology of chronic maxillary sinusitis in adults. Ann Otol Rhinol Laryngol 1989; 98:426–428. 91. Brook I. Brain abscess in children: microbiology and management. Child Neurol 1995; 10:283–288. 92. Westrin KM, Stierna P, Carlsoo B, Hellstrom S. Mucosal ﬁne structure in experimental sinusitis. Ann Otol Rhinol Laryngol 1993; 102(8 Pt 1): 639–645. 93. Jyonouchi H, Sun S, Kennedy CA, Roche AK, Kajander KC, Miller JR, Germaine GR, Rimell FL. Localized sinus inﬂammation in a rabbit sinusitis model induced by Bacteroides fragilis is accompanied by rigorous immune responses. Otolaryngol Head Neck Surg 1999; 120:869–875. 94. Brook I, Yocum P. Immune response to Fusobacterium nucleatum and Prevotella intermedia in patients with chronic maxillary sinusitis. Ann Otol Rhinol Laryngol 1999; 108:293–295. 95. Brook I, Yocum P, Frazier EH. Bacteriology and beta-lactamase activity in acute and chronic maxillary sinusitis. Arch Otolaryngol Head Neck Surg 1996; 122:418–422. 96. Brook I, Yocum P, Shah K. Aerobic and anaerobic bacteriology of concurrent chronic otitis media with effusion and chronic sinusitis in children. Arch Otolaryngol Head Neck Surg 2000; 126:174–176. 97. Orobello PW Jr, Park RI, Belcher L, et al. Microbiology of chronic sinusitis in children. Arch Otolaryngol Head Neck Surg 1991; 117:980–983. 98. Tinkleman DG, Silk HJ. Clinical and bacteriologic features of chronic sinusitis in children. Am J Dis Child 1989; 143:938–941. 99. Muntz HR, Lusk RP. Bacteriology of the ethmoid bullae in children with chronic sinusitis. Arch Otolaryngol Head Neck Surg 1991; 117:179–181. 100. Otten FWA, Grote JJ. Treatment of chronic maxillary sinusitis in children. Int J Pediatr Otorhinolaryngol 1988; 15:269–278. 101. Otten FWA. Conservative treatment of chronic maxillary sinusitis in children. Long term follow-up. Acta Otol Rhinol Laryngol Belg 1997; 51:173–175. 102. Don D, Yellon RF, Casselbrant M, Bluestone CD. Efﬁcacy of stepwise protocol that includes intravenous antibiotic treatment for the management of chronic sinusitis in children and adolescents. Otolaryngol Head Neck Surg 2001; 127:1093–1098.

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103. Erkan M, Ozcan M, Arslan S, Soysal V, Bozdemir K, Haghighi N. Bacteriology of antrum in children with chronic maxillary sinusitis. Scand J Infect Dis 1996; 28:283–285. 104. Slack CL, Dahn KA, Abzug MJ, Chan KH. Antibiotic-resistant bacteria in pediatric chronic sinusitis. Pediatr Infect Dis J 2001; 20:247–250. 105. Goldenhersh MJ, Rachelefsky GS, Dudley J, Brill J, Katz RM, Rohr AS, Spector SL, Siegel SC, Summanen P, Baron EJ. The microbiology of chronic sinus disease in children with respiratory allergy. J Allergy Clin Immunol 1990; 85:1030–1039. 106. Wald ER, Byers C, Guerra N, et al. Subacute sinusitis in children. J Pediatr 1989; 115:28–32. 107. Brook I, Yocum P. Antimicrobial management of chronic sinusitis in children. J Laryngol Otol 1995; 109:1159–1162. 108. Finegold SM. Anaerobic bacteria in human disease. Orlando, FL: Academic Press, Inc., 1977. 109. Brook I. Pediatric Anaerobic Infections. 3rd. NY: Marcel Dekker Inc, 2002. ¨ , Nedret K. Bacteriology of antrum in adults 110. Mustafa E, Tahsin A, Mustafa O with chronic maxillary sinusitis. Laryngoscope 1994; 104:321–324. 111. Frederick J, Braude AI. Anaerobic infections of the paranasal sinuses. N Engl J Med 1974; 290:135–137. 112. Van Cauwenberge P, Verschraegen G, Van Renterghem L. Bacteriological ﬁndings in sinusitis (1963–1975). Scand J Infect Dis Suppl 1976; 9:72–77. 113. Karma P, Jokipii L, Sipila P, Luotonen J, Jokipii AM. Bacteria in chronic maxillary sinusitis. Arch Otolaryngol 1979; 105:386–390. 114. Berg O, Carenfelt C, Kronvall G. Bacteriology of maxillary sinusitis in relation to character of inﬂammation and prior treatment. Scand J Infect Dis 1988; 20(5):511–516. 115. Fiscella RG, Chow JM. Ceﬁxime for the treatment of maxillary sinusitis. Am J Rhinol 1991(2,5):193–197. 116. Sedallian AB, Bru JP, Gaillat J. Bacteriologic ﬁnding of chronic sinusitis. (Abstr no. P2.71). The 17th International Congress of the Management of Infection. Berlin, 1992. 117. Simoncelli C, Ricci G, Molini E, von Garrel C, Capolunghi B, Giommetti S. Bacteriology of chronic maxillary sinusitis. HNO 1992; 40:16–18. 118. Tabaqchali S. Anaerobic infections in the head and neck region. Scand J Infect Dis Suppl 1988; 57:24–34. 119. Hartog B, Degener JE, Van Benthem PP, Hordijk GJ. Microbiology of chronic maxillary sinusitis in adults: isolated aerobic and anaerobic bacteria and their susceptibility to twenty antibiotics. Acta Otolaryngol 1995; 115:672–677. 120. Ito K, Ito Y, Mizuta K, Ogawa H, Suzuki T, Miyata H, Kato N, Watanabe K, Ueno K. Bacteriology of chronic otitis media, chronic sinusitis, and paranasal mucopyocele in Japan. Clin Infect Dis 1995; 20(suppl 2):S214–S219. 121. Erkan M, Aslan T, Ozcan M, Koc N. Bacteriology of antrum in adults with chronic maxillary sinusitis. Laryngoscope 1994; 104(3 Pt 1):321–324. 122. Edelstein DR, Avner SE, Chow JM, Ouerksen RL, Johnson J, Ronis M, Rybak LP, Bierman WC, Matthews BL. Once-a-day therapy for sinusitis:

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a comparison study of ceﬁxime and amoxicillin. Laryngoscope 1993; 103:33–41. 123. Klossek JM, Dubreuil L, Richet H, Richet B, Beutter P. Bacteriology of chronic purulent secretions in chronic rhinosinusitis. J Laryngol Otol 1998; 112:1162–1166. 124. Brook I, Frazier EH. Correlation between microbiology and previous sinus surgery in patients with chronic maxillary sinusitis. Ann Otol Rhinol Laryngol 2001; 110:148–151. 125. Brook I. Bacteriology of acute and chronic frontal sinusitis. Arch Otolaryngol Head Neck Surg 2002; 128:583–585. 126. Brook I. Bacteriology of acute and chronic sphenoid sinusitis. Ann Otol Rhinol Laryngol 2002; 111:1002–1004. 127. Brook I. Bacteriology of acute and chronic ethmoid sinusitis. J Clin Microb 2005; 43:3479–3480. 128a. Bhattacharyya N, Kepnes LJ. The microbiology of recurrent rhinosinusitis after endoscopic sinus surgery. Arch Otolaryngol Head Neck Surg 1999; 125:1117–1120. 128b. Bucholtz GA, Salzman SA, Bersalona FB, Boyle TR, Ejercito VS, Penno L, Peterson DW, Stone GE, Urquhart A, Shukla SK, Burmester JK. PCR analysis of nasal polyps, chronic sinusitis, and hypertrophied turbinates for DNA encoding bacterial 16S rRNA. Am J Rhinol 2002; 16:169–173. 128c. Hamilos DL, Leung DYM, Wood R, Meyers A, Stephens JK, Barkans J, Bean DK, Kay AB, Hamid Q. Association of tissue eosinophilia and cytokine mRNA expression of granulocyte-macrophage colony-stimulating factor and interleukin-3. J Allergy Clin Immunol 1993; 91:39–48. 128d. Brook I, Frazier EH. Bacteriology of chronic maxillary sinusitis associated with nasal polyposis. J Med Microbiol 2005; 54:595–597. 129. Clement PA, Bluestone CD, Gordts F, Lusk RP, Otten FW, Goossens H, Scadding GK, Takahashi H, van Buchem FL, Van Cauwenberge P, Wald ER. Management of rhinosinusitis in children: consensus meeting, Brussels, Belgium, September 13, 1996. Arch Otolaryngol Head Neck Surg 1998; 124:31–34. 130. Brook I, Foote PA, Frazier EH. Microbiology of acute exacerbation of chronic sinusitis. Laryngoscope 2004; 114:129–131. 131. Brook I. Bacteriology of chronic sinusitis and acute exacerbation of chronic sinusitis. Annals Otolary Head Neck Surg. 132. Bach A, Boehrer H, Schmidt H, Geiss HK. Nosocomial sinusitis in ventilated patients: nasotracheal versus orotracheal intubation. Anaesthesia 1992; 47:335–339. 133. O’Reilly MJ, Reddick EJ, Black W, Carter PL, Erhardt J, Fill W, Maughn D, Sado A, Klatt GR. Sepsis from sinusitis in nasotracheally intubated patients: a diagnostic dilemma. Am J Surg 1984; 147:601–604. 134. Mevio E, Benazzo M, Quaglieri S, Mencherini S. Sinus infection in intensive care patients. Rhinology 1996; 34:232–236. 135. Caplan ES, Hoyt NJ. Nosocomial sinusitis. JAMA 1982; 247:639–641. 136. Kronberg FG, Goodwin WJ. Sinusitis in intensive care unit patients. Laryngoscope 1985; 95:936–938.

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156. Adam RD, Paquin ML, Petersen EA, Saubolle MA, Rinaldi MG, Corcoran JN, Solaonya RE. Phaeohyphomycosis caused by the fungal general Bipolaris and Exserohilum. Medicine 1986; 65:203–217. 157. Zieske LA, Kople RD, Hamill R. Dermataceous fungal sinusitis. Otolaryngol Head Neck Surg 1991; 105:567–577. 158. Goldstein MF, Dvorin DJ, Dunsky EH, Lesser RW, Heuman PJ, Loose JH. Allergic rhizomucor sinusitis. J Allergy Immun 1992; 90:394–404. 159. Katzenstein A, Sale SR, Greenberger PA. Pathologic ﬁndings in allergic Aspergillus sinusitis. Am J Surg Pathol 1983; 7:439–443. 160. Maran ACD, Kwong K, Mine LJR, Lamb D. Frontal sinusitis caused by Myriodontium keratinophilum. Br Med J 1985; 290:207. 161. Friedman GC, Hartwick RW, Ro JY, et al. Allergic fungal sinusitis. Report of three cases associated with dermataceous fungi. Am J Clin Pathol 1991; 96:368–372. 162. Bartynski JM, McCaffrey TV, Frigas E. Allergic fungal sinusitis secondary to dermataceous fungi—Curvularia lunata and Alternaria. Otolaryngol Head Neck Surg 1990; 103:32–39.

SECTION IV. THERAPEUTIC OPTIONS

9 Antimicrobial Management of Sinusitis Itzhak Brook Departments of Pediatrics and Medicine, Georgetown University School of Medicine, Washington, D.C., U.S.A.

INTRODUCTION The growing resistance to antimicrobial agents of all respiratory tract bacterial pathogens has made the management of sinusitis more difﬁcult. This chapter presents the current information regarding the antimicrobial resistance of the organisms involved in sinusitis and the approaches to antimicrobial therapy. ANTIMICROBIAL RESISTANCE To manage bacterial sinusitis is often a challenging endeavor in which selection of the most appropriate antimicrobial agents remains a key decision. This has become more difﬁcult in recent years as all the predominant bacterial pathogens have gradually developed resistance to most of the commonly used antibiotics. The observed increase in bacterial resistance to antibiotics is related to their frequent use. Previous therapy can increase the prevalence of betalactamase-producing bacteria (BLPB). In a study of 26 children who had received seven days of therapy with penicillin, 12% harbored BLPB in their oropharyngeal ﬂora prior to therapy (1). This increased to 46% at the conclusion of therapy, and the incidence was 27% after three months. The incidence of BLPB was high in siblings and parents of patients treated with penicillin, who probably acquired these organisms from the patient (2).

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A greater prevalence of recovery of BLPB in the oropharynx of children occurs in the winter and a lower one in the summer (3). These changes correlated with the intake of beta-lactam antibiotics. To monitor the local seasonal variations in the rate of recovery of BLPB in the community may help the empirical choice of antimicrobial agents, the proper and judicious use of which may help to control the increase of BLPB. Risk factors for the development of resistance to antimicrobial agents include prior antibiotic exposure, day care attendance, age under two years, recent hospitalization, and recurrent infection (especially in those who are very young or very old) (4,5). The variety of organisms involved in sinusitis, increasing levels of resistance to antibiotic agents, and the phenomenon of beta-lactamase ‘‘shielding’’ from antibiotic agents all contribute to the therapeutic challenges associated with the management of acute and chronic sinusitis. Brook and Gober (5) identiﬁed the antimicrobial susceptibility of the pathogens isolated from patients with maxillary sinusitis who failed to respond to antimicrobial therapy and correlates it with previous antimicrobial therapy and smoking. The data illustrated a relationship between resistance to antimicrobials and failure of patients with sinusitis to improve. A statistically signiﬁcant higher recovery of resistant organisms was noted in those treated two to six months previously, and in those who smoked. Three major mechanisms of resistance to penicillins occur: 1. Porin channel blockage (e.g., used by Pseudomonas spp. to resist carbapenems) 2. Production of the enzyme beta-lactamase (e.g., utilized by Haemophilus inﬂuenzae and Moraxella catarrhalis). 3. Alterations in the penicillin-binding protein (e.g., used by Streptococcus pneumoniae). BETA-LACTAMASE PRODUCTION Bacterial resistance to the antibiotics used for the treatment of sinusitis has been increased consistently in recent years. Production of the enzyme betalactamase is one of the most important mechanisms of penicillin resistance. The production of the enzyme beta-lactamase is an important mechanism of virulence of anaerobic gram-negative bacilli as well as other aerobic and anaerobic bacteria. The production of beta-lactamase can have wider implication than just protecting the bacteria that produces the enzyme. In polymicrobial infections BLPB can ‘‘shield’’ other co-pathogens that are penicillin-susceptible (6,7) (Fig. 2 in Chap. 8). It has been hypothesized that this protection can occur when the enzyme beta-lactamase is secreted into the infected tissues or sinus ﬂuids in sufﬁcient quantities to break the penicillin’s beta-lactam ring before it can kill the susceptible bacteria, thus contributing to treatment failure.

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The emergence and persistence of BLPB after antibiotic therapy has implications for antimicrobial selection for in treatment of sinusitis as well as other infections of the upper respiratory tract, particularly chronic conditions in which patients are likely to have had recent antibiotic exposure. Clinical and laboratory studies provide support for this hypothesis. Animal studies demonstrated the ability of the enzyme beta-lactamase to inﬂuence polymicrobial infections. Hackman and Wilkins (8) showed that penicillin-resistant strains of Bacteroides fragilis, pigmented Prevotella and Porphyromonas spp., and Prevotella oralis protected a penicillin-sensitive Fusobacterium necrophorum from penicillin therapy in mice. Using a subcutaneous abscess model in mice, Brook et al. (9) demonstrated protection of group A beta-hemolytic streptococci (GABHS) from penicillin by B. fragilis and Prevotella melaninogenica. Clindamycin or the combination of penicillin and clavulanic acid (a beta-lactamase inhibitor), which are active against both GABHS and anaerobic gram-negative bacilli, were effective in eradicating the infection. Similarly, betalactamase–producing facultative bacteria protected a penicillin-susceptible P. melaninogenica from penicillin (10). In vitro studies have also demonstrated this phenomenon. A 200-fold increase in resistance of GABHS to penicillin was observed when it was inoculated with Staphylococcus aureus (11). An increase in resistance was also noted when GABHS was grown with Haemophilus parainﬂuenzae (12). When mixed with cultures of B. fragilis, the resistance of GABHS to penicillin increased 8500-fold (13). Several species of BLPB occur in sinusitis (Table 1). BLPB have been recovered from over one-third of patients with sinusitis (14,15). H. inﬂuenzae and M. catarrhalis are the predominant BLPB in acute sinusitis, and S. aureus, pigmented Prevotella, Porphyromonas, and Fusobacterium spp. predominate in chronic sinusitis.

Table 1 Resistance to Antimicrobial Agents in Bacterial Sinusitis Bacteria Acute sinusitis S. pneumoniae H. inﬂuenzaea M. catarrhalisa Chronic sinusitis S. aureusa Pigmented Prevotellaa and Porphyromonasa spp. Fusobacteriuma spp. a

Incidence (%)

Resistance to penicillin (%)

30–40 25–30 10–15

20–40 30–40 95

10–35 15–30

95 10–60

15–40

10–60

Resistance due to beta-lactamase production.

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Table 2 Beta-Lactamase Detected in Four Acute Bacterial Sinusitis Aspirates Obtained from Patients Treated with Amoxicillin Patient Organism

1a

2a

S. pneumoniae M. catarrhalis (beta-lactamase positive) H. inﬂuenzae (beta-lactamase positive) Beta-lactamase activity in pus

þ þ

þ

3 þ

þ þ

4

þ

þ

–

þ

a ‘‘Shielding’’ of S. pneumoniae by beta-lactamase producers is evident in patients 1 and 2. Source: Data from Ref. 7.

The actual activity of the enzyme beta-lactamase and the potential of the presence of the phenomenon of ‘‘shielding’’ were demonstrated in acutely and chronically inﬂamed sinus ﬂuids (7). BLPB were isolated in four of 10 acute sinusitis aspirates and in 10 of 13 chronic sinusitis aspirates (Tables 2 and 3). The predominant BLPB isolated in acute sinusitis were H. inﬂuenzae and M. catarrhalis, and those found in chronic sinusitis were S. aureus, B. fragilis, and Prevotella and Fusobacterium spp. (7). ‘‘Free’’ betalactamase was detected in 86% of aspirates that contained these organisms,

Table 3 Beta-Lactamase Detected in Four Chronic Bacterial Sinusitis Aspirates Obtained from Patients Treated with Amoxicillin Patient Organism S. aureus BL (þ) S. pneumoniae Peptostreptococcus spp. Propionibacterium acnes Fusobacterium spp. BL (þ) Fusobacterium spp. BL () Prevotella spp. BL (þ) Prevotella spp. BL () Bacteroides fragilis group BL (þ) Beta-Lactamase activity in pus

1

2

3

þ

þ

þ þ þ

þ þ þ

þ þ þ

4

þ þ

þ

þ þ

þ

þ

a ‘‘Shielding’’ is present in all cases. Abbreviation: BL (þ), beta-lactamase–producing organism. Source: Data from Ref. 7.

þ þ

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and was associated with persistence of even penicillin-susceptible pathogens despite antimicrobial therapy. Haemophilus influenzae Resistance to Antimicrobials Resistance to beta-lactams among strains of H. inﬂuenzae has increased throughout the past three decades. In the 1980s, the prevalence of betalactamase–producing H. inﬂuenzae was between 10% and 15% (16,17). Resistance among strains of H. inﬂuenzae increased steadily throughout the 1990s, and presently approximately 40% of H. inﬂuenzae strains are beta-lactamase producers. Beta-lactamase–producing strains of H. inﬂuenzae are most prevalent in the northcentral, northeast, and southcentral regions of the United States (18). Generally, higher doses of beta-lactams are not effective in overcoming this mechanism of resistance; however, the addition of a beta-lactamase inhibitor (e.g., clavulanic acid) shifts H. inﬂuenzae strains to the susceptible range [e.g., minimal inhibitory concentration (MIC) 4 mg/mL], transforming the susceptibilities to those of beta-lactamase–negative strains. Agents that are stable in the presence of beta-lactamases are another option for treating infections caused by this pathogen. Among the oral beta-lactam antibiotics, amoxicillin/clavulanate (because of the beta-lactamase inhibitor), ceﬁxime, ceftibuten, cefdinir, and cefpodoxime are highly active against beta-lactamase–producing H. inﬂuenzae (19). Macrolides in general have limited activity against H. inﬂuenzae; among the three agents (i.e., erythromycin, clarithromycin, and azithromycin), clarithromycin is least active against H. inﬂuenzae (20). Inhibition of H. inﬂuenzae by macrolides is dependent on the ability to achieve concentrations above the MICs at the site of infection. Based on pharmacokinetic/pharmacodynamic (PK/PD) breakpoints, the MICs of virtually all H. inﬂuenzae strains in the 1998 surveillance study were below PK/PD breakpoints (i.e., resistant) for erythromycin, clarithromycin, and azithromycin. Furthermore, azithromycin failed to eradicate 61% of H. inﬂuenzae from the middle ear of children with otitis media (21). Resistance to trimethoprim-sulfamethoxazole (TMP/SMX) was exhibited among 24% of isolates. Fluoroquinolones, particularly the newer agents, are very active against H. inﬂuenzae, with relatively no resistance according to the recent surveillance data (20). Moraxella catarrhalis Resistance to Antimicrobials Virtually all strains of M. catarrhalis produce beta-lactamase. The 1998 prevalence among outpatient isolates for beta-lactamase–producing M. catarrhalis was 98% (19). At PK/PD breakpoints, 100% of strains were susceptible to amoxicillin/clavulanate, ﬂuoroquinolones, macrolides, doxycycline, and ceﬁxime. High levels of resistance were exhibited toward TMP/SMX, cefaclor, loracarbef, cefprozil, and amoxicillin.

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Streptococcus pneumoniae Resistance to Antimicrobials Penicillin Resistance Resistance among S. pneumoniae strains has been monitored in the United States since 1979. Prior to the 1990s, resistance to penicillin was not considered a clinical problem in the United States. Throughout the past decade, the prevalence of S. pneumoniae isolates that are either intermediate (i.e., penicillin MICs 0.12–1.0 mg/mL) or resistant to penicillin (i.e., MICs2.0 mg/mL) has increased, with dramatic increases within the past few years (22). The incidence of penicillin-resistance in strains of S. pneumoniae approaches 40% in some areas of the United States, and the incidence of high-level resistance has increased by 60-fold during the past 10 years. The mechanism of beta-lactam-resistance of S. pneumoniae involves genetic mutations that alter penicillin-binding protein structure, resulting in a decreased afﬁnity for all beta-lactam antibiotics. About half of the penicillin-resistant strains are currently intermediately resistant [minimal inhibitory concentration (MIC) of 0.1–1.0 mg/mL] and the rest are highly resistant (MIC > 2.0 mg/mL). It is important to note, however, that this change in MIC does not confer absolute resistance to all beta-lactams because the pharmacokinetics of each agent need to be considered. Thus, strains of S. pneumoniae with penicillin MICs 2 mg/mL (i.e., resistant) are not necessarily resistant to other beta-lactams (e.g., amoxicillin). Resistance to beta-lactams represents a pharmacokinetic challenge that can be overcome if a high enough concentration of beta-lactam can be achieved at the site of infection. Penicillin-resistant strains are often also resistant to other antimicrobial agents commonly used to treat sinusitis (Table 4). The term drug-resistant S. pneumoniae refers to strains with penicillin MICs 0.12 mg/mL that also exhibit resistance to at least two other antimicrobial classes. The susceptibility of S. pneumoniae isolates to other antimicrobials is closely correlated to its susceptibility to penicillin. However, these strains are susceptible to parenteral third-generation cephalosporins (i.e., cefotaxime, ceftriaxone), the ﬂuoroquinolones (levoﬂoxacin, gatiﬂoxacin, moxiﬂoxacin, gemiﬂoxacin), vancomycin, quinupristin with dalfopristin, telithromycin and linezolid. Intermediately resistant S. pneumoniae are still susceptible in vitro to high doses of penicillin or amoxicillin (23). Clindamycin and the oral second-generation cephalosporins, especially cefuroxime axetil and cefprozil, are also effective in vitro against over 95% of intermediately penicillin-resistant strains (24). The regions of the United States with the highest proportion of penicillin-, macrolide-, and trimethoprim/sulfamethoxazole-resistant S. pneumoniae strains are the southcentral and southeast. The reason for increased resistance in these regions is not currently known, and the variation is not signiﬁcant enough to warrant different antimicrobial recommendations for each region. Although penicillin-resistant strains are common in all age groups, the highest proportions of resistant strains are collected from

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Table 4 Cross-Resistance of Penicillin-Resistant S. pneumoniae Cross-resistance (%) Antimicrobial agent

Intermediately resistanta

Highly resistantb

52

91.9

22.8 49.8 13.1

47.4 80.4 25.3

60

95

5 10 2.2 2.1 0.1

10 20 2.2 1.9 0.6

Trimethoprimsulfamethoxazole Tetracycline Macrolides Clindamycin Third-generation cephalosporins: Oral (ceﬁxime, ceftibuten) Parenteral (ceftriaxone) Rifampin Levoﬂoxacin Gatiﬂoxacin Telithromyicn a

MIC 0.12–1.0 mg/mL. MIC 2.0 mg/mL.

b

children younger than two years. In addition, resistant strains are most likely to be isolated from middle ear (approximately 58% of all S. pneumoniae isolates), sinus (approximately 60% of all S. pneumoniae isolates), and nasopharyngeal specimens (approximately 55% of all S. pneumoniae isolates) (25). Many of these cultures were obtained from treatment failures, however, and the true prevalence of resistance in specimens isolated from these sites may be somewhat lower. Macrolide-Resistance Macrolide-resistance among S. pneumoniae has escalated at alarming rates in North America and worldwide. Macrolide-resistance among pneumococci is primarily due to genetic mutations affecting the ribosomal target site (ermAM) or active drug efﬂux (mefE). Ribosomal mutations that confer high-grade resistance are also cross-resistant to clindamycin, whereas efﬂux mutations can likely be overridden in vivo (26). Currently, about a third of macrolide-resistant strains in North America possess the efﬂux mutations mechanism of resistance, and the rest exhibit the ribosomal mutations. This relationship is reversed in Europe and the Far East, where most resistance is conveyed through the ribosomal mutations mechanism. Pneumococci resistant to erythromycin (by either mechanism) are also resistant to azithromycin, clarithromycin, and roxithromycin (27). Prior antibiotic exposure is the major risk factor for ampliﬁcation and perpetuation of resistance. Clonal

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spread facilitates dissemination of drug-resistant strains. Several population-based studies noted correlations between the prevalence of macrolide resistance among S. pneumoniae and overall macrolide consumption in the region or country (28,29). Fluoroquinolone-Resistance The main resistance mechanisms to ﬂuoroquinolones are the efﬂux pump system and speciﬁc point mutations. The efﬂux pump is a mechanism that expells the antimicrobial agent across the cell membrane, thus reducing the intracellular concentrations to sublethal levels. The pump’s action is dependent on the antimicrobial’s ability to bind to the bacterial efﬂux protein and to be exported. Some ﬂuoroquinolones, such as moxiﬂoxacin and trovaﬂoxacin, are not as affected by bacterial efﬂux mechanisms because of their bulky side-chain moiety at position 7, which prevents export (30). The other resistance mechanism involves speciﬁc point mutations that reduce the binding of the antimicrobial to speciﬁc enzymatic sites by altering the target site. In this regard, ﬂuoroquinolones bind to enzymes involved in DNA replication, including DNA gyrase and DNA topoisomerase IV. Speciﬁc mutations in the genes that code for these enzymes can result in reduced binding and activity of the ﬂuoroquinolones (31). Different ﬂuoroquinolones exhibit weaker or stronger afﬁnity to these enzyme-binding sites. First- and second-generation ﬂuoroquinolones bind primarily to DNA gyrase or DNA topoisomerase IV, whereas the third-generation ﬂuoroquinolones generally bind strongly to both DNA gyrase and DNA topoisomerase IV. Thus, a single point mutation in DNA gyrase or DNA topoisomerase IV generally affects ﬁrst- and second-generation ﬂuoroquinolones to a greater extent than third-generation ﬂuoroquinolones. Furthermore, the third-generation C-8 methoxyﬂuoroquinolones, moxiﬂoxacin and gatiﬂoxacin, appear to bind different molecular sites within these enzymes, thereby decreasing the cross-resistance between these agents and the older ﬂuoroquinolones (32). Microbial resistance to the newer ﬂuoroquinolones (levoﬂoxacin, gatiﬂoxacin, moxiﬂoxacin and gemiﬂoxacin) is relatively uncommon, currently occurring in approximately 1% of clinical isolates in North America. However, increased resistance has been observed in the some countries (33). These agents can be useful for treatment of bacterial sinusitis, but caution must be exercised to avoid the potential for selection of widespread resistance, which may occur with indiscriminate use (34).

ANTIMICROBIAL AGENTS The antimicrobial agents most commonly used to treat acute sinusitis include amoxicillin (with and without clavulanic acid), oral and parenteral cephalosporins, macrolides, and ‘‘newer’’ quinolones (Tables 5 and 6).

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Table 5 Antibiotics Used for Bacterial Sinusitis (PO)

Antibiotic Beta-lactams Cefprozil (Cefzil) Cefuroxime axetil (Ceftin) Cefpodoxime (Vantin) Cefdinir (Omnicef) Amoxicillin (Amoxil, Trimox, Wymox) Amoxicillin-clavulanate (Augmentin)

Ketolides Telithromycin (Ketek) Macrolides Azithromycin (Zithromax) Clarithromycin (Biaxin) Fluoroquinolones Levoﬂoxacin (Levaquin) Gatiﬂoxacin (Tequin) Moxiﬂoxacin (Avelox) Others Clindamycin (Cleocin) TMP-SMX (Bactrim, Septra)

Adult dosage 250–500 mg bid 250–500 mg bid 200–400 mg bid 300 mg bid 500 mg tid or 875 mg bid 500 mg tida or 875 mg or 2000 mg (XR) bida

Duration of therapy for acute sinusitis Pediatric (days) dosage (mg/kg) 7.5–15 bid 10–15 bid 5 bid 7 bid/14 qd 20–45 bid

10 10 10 10 14

22.5 or 45 (ES600) bid

10

800 mg qd

NA

5

250 mg qd 500 mg bid

10 day 1, then 5 qd 7.5 bid

500 mg qd 500 mg qd 400 mg qd

NA NA NA

10 10 10

150–450 mg tid or qid 160 mg/800 mg bid

7.5 qid or 6 tid

10

8–12 bid

10

3 or 5 14

a

Based on amoxicillin component. Abbreviation: NA, not approved for patients <18 years of age.

Amoxicillin is often used for sinusitis therapy and is safe and inexpensive, and when given in a high dose, it is still the drug of choice for intermediately penicillin-susceptible S. pneumoniae. However, the growing resistance of H. inﬂuenzae and M. catarrhalis to amoxicillin through the production of betalactamase increases the risk that it will fail to clear the infection. However, the addition of clavulanic acid (a beta-lactamase inhibitor) to amoxicillin or the use of antimicrobial agents resistant to beta-lactamase activity is effective against resistant organisms. Using higher doses of amoxicillin clavulanate (i.e., 4.0 g/day in adults or 90 mg/kg/day in children based on amoxicillin component) will help to

Amoxicillin Amoxicillin-clavulanate Cephalexin (ﬁrst-generation) Cefactor (second-generation) Cefprozil (second-generation) Cefuroxime axetil (second-generation) Cefpodoxime (second-generation) Cefdinir (second-generation) Ceﬁxime (third-generation) Ceftibuten (third-generation) Loracarbef Ceftriaxoneb Erythromycin-sulﬁsoxazole Trimethoprim-sulfamethoxazole

Antimicrobial agent

Pen-IR þ þ þ þ þ

Pen-S þ þ þ þ þ þ þ þ þ þ

S. pneumoniae

þ þ þ þ þ þ þ þ þ þ þ þ þ

BL þ þ þ þ þ þ þ þ

BLþ

H. inﬂuenzae

þ þ þ þ þ þ þ þ þ

BLþ

M. catarrhalis

Table 6 In Vitro Efﬁcacy of Antimicrobial Agents Used in Bacterial Sinusitis Therapy

þ þ þ þ þ þ þ þ þ þ

Pen-S

þ

Pen-R

Anaerobes

þ þ þ þ þ þ þ

Pen-Ra

S. aureus

188 Brook

þ þ þ þ þ þ þ þ þ

þ þ – þ þ þ

þ þ þ þ þ þ

þ þ þ þ þ þ

þ þ þ þ þ þ þ

þ þ þ þ þ

þ þ

þ þ þ þ þ þ þ

b

þ, very susceptible; , minimal susceptibility; , not susceptible. Methicillin susceptible. Available in parental form only. c Available (also) in parenteral form. d Imipenem-cilastatin, meropenem, ertapenem. Abbreviations: BL, beta-lactamase non-producers; BLþ, beta-lactamase producers; Pen-S, penicillin susceptible; Pen-R, penicillin resistance; Pen-IR, penicillin intermediate resistance.

a

Erythromycin Azithromycin Clarithromycin Telithromycin Clindamycin Ciproﬂoxacin Levoﬂoxacin Gatiﬂoxacin Moxiﬂoxacin Carbapenemsb

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ensure adequate eradication of penicillin-resistant S. pneumoniae organisms (34). Amoxicillin/clavulanate is also active against anaerobic bacteria, which is an important consideration in patients with chronic sinusitis. First-generation cephalosporins lack sufﬁcient efﬁcacy against H. inﬂuenzae and many S. pneumoniae strains. Generally, cefaclor and loracarbef are not considered effective for the treatment of acute sinusitis because of the limited activity of these agents. The second-generation cephalosporins (cefuroxime axetil, cefdinir, cefpodoxime, and cefprozil) are more effective because of their activity against penicillin-resistant Haemophilus and Moraxella spp. and intermediately penicillin-resistant S. pneumoniae (24). Oral third-generation cephalosporins (ceﬁxime and ceftibuten) are most effective against penicillin-resistant Haemophilus and Moraxella spp., but they are less effective against S. pneumoniae resistant to penicillin. Parenteral thirdgeneration cephalosporins (cefotaxime or ceftriaxone) are effective against H. inﬂuenzae and M. catarrhalis that produce beta-lactamase, as well as over 95% of intermediately resistant S. pneumoniae. No oral cephalosporin is active against anaerobes, which is an important consideration for the treatment of chronic sinusitis. TMP/SMX has lost efﬁcacy against all major pathogens, including S. pneumoniae and GABHS. The sulfa component can cause hypersensitivity reactions. Of the macrolides, erythromycin is inactive against H. inﬂuenzae and some GABHS. Resistance of GABHS to erythromycin and other macrolides occurs in countries where these agents were overused (e.g., Japan, Finland, Spain, Taiwan and Turkey) (35). Cross-resistance of GABHS is common among all macrolides. Azithromycin has improved efﬁcacy against aerobic gram-negative organisms (H. inﬂuenzae and M. catarrhalis), while clarithromycin is more efﬁcient than erythromycin against aerobic gram-positive organisms (36). Recent studies show, however, increased resistance of S. pneumoniae to all macrolides (up to 35%), and survival of azithromycin-susceptible H. inﬂuenzae in the middle ear and sinuses (21, 37). The persistence of the organism in otitis media is believed to result from accumulation of azithromycin mainly inside the middle ear white cells, and not in the middle ear ﬂuid where most of the organisms grow. Clindamycin is effective against anaerobes and aerobic gram-positive organisms, including most penicillin-resistant S. pneumoniae; however, it is not effective against aerobic gram-negative pathogens. Vancomycin (a glycopeptide) and linezolid are effective against penicillin-resistant S. pneumoniae and methicillin-resistant S. aureus. However, they are not effective against H. inﬂuenzae or M. catarrhalis. Telithromycin is the ﬁrst ketolide antibacterial to be approved for clinical use. It is structurally related to the macrolides, but has a low propensity to select for or induce resistance to macrolide-lincosamide-streptogramin antibacterials (38). In vitro, telithromycin is effective against multi-drug-resistant S. pneumoniae (regardless of the presence of macrolide-resistant determinants

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[erm(B), mef(A)]), GABHS, M. catarrhalis, and H. inﬂuenzae. In clinical trials, it has demonstrated clinical and bacteriological efﬁcacy in the treatment of acute sinusitis due to penicillin and/or macrolide (erythromycin) resistant S. pneumoniae as well as H. inﬂuenzae or M. catarrhalis (39). The ﬁrst-generation ﬂuoroquinolones (e.g., ciproﬂoxacin, oﬂoxacin) provide inadequate S. pneumoniae coverage and are primarily active against aerobic gram-negative bacilli (including H. inﬂuenzae and M. catarrhalis). The secondgeneration ﬂuoroquinolone, levoﬂoxacin, is the L-isomer of oﬂoxacin and demonstrates somewhat-improved gram-positive activity. However, susceptibility data show levoﬂoxacin to be less potent than ciproﬂoxacin against such gram-negative pathogens as Pseudomonas aeruginosa and certain enterobacteriaceae. The third-generation ﬂuoroquinolones include moxiﬂoxacin, gemiﬂoxacin, and gatiﬂoxacin and have improved gram-positive and atypical bacteria coverage compared with ﬁrst- and second-generation ﬂuoroquinolones. Some of the newer ﬂuoroquinolones (e.g., gatiﬂoxacin, moxiﬂoxacin, trovaﬂoxacin) have activity against oral anaerobes, but their efﬁcacy in chronic sinusitis has not been proven. In particular, these newer representatives of the ﬂuoroquinolone class manifest greater activity against S. pneumoniae (40). A major concern with the use of these agents, however, is the selection of class resistance to gramnegative organisms, staphylococci, and pneumococci (19,20). None of the newer ﬂuoroquinolones is currently approved for use in children. Pharmacokinetics and Pharmacodynamics (PK/PD) of Antimicrobials The goal of antibiotic therapy is to eradicate the causative organism from the sinus cavity. To achieve this goal, the antibiotic must be active in vitro against the targeted organisms and must penetrate the sinus cavity in sufﬁcient concentrations. The effect of antibiotics in eliminating the organisms is an added effect over the natural eradication achieved in time by the host. The host defenses that participate in this process include activity of inﬂammatory cells, antibody, complement, and other host defense mechanisms. The environment at the infected sinus never corresponds to the laboratory in vitro susceptibility testing conditions. The actual performance of an antibiotic in vivo depends on variables that include the oxygen tension, pH, and protein binding of an antibiotic. Several methods are utilized to evaluate the in vitro activity of an antibiotic. Most often a MIC or a minimum bactericidal concentration (MBC) is determined to assess antibiotic activity. The utility and limitations of these tests should be appreciated. The MIC and MBC are values characterizing an antibiotic under strict test tube conditions, and clinical interpretation also requires the consideration of PK/PD issues. Although standard parameters of antimicrobial activity such as MIC and minimal bactericidal concentration are helpful, they do not provide

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information about the time course or rate of kill relative to concentration or whether post-antibiotic effects contribute to activity (41). The pharmacology of antimicrobial chemotherapy in sinusitis can be divided into two components (41): 1. pharmacokinetic component—this pertains to the dosing regimen, drug absorption, distribution, protein binding, bioavailability, half-life, metabolism, and elimination, which determine the time course of the drug concentrations in serum, sinus ﬂuid, and sinus mucosal tissues 2. pharmacodynamic component—this deals with the association between concentrations of the drug at the site of infection and its antimicrobial effect Antibiotics can be divided into two major groups: those that exhibit concentration-dependent killing and prolonged persistent effects and those that exhibit time-dependent killing and minimal-to-moderate persistent effects (41). With drugs that fall into the former group, the area under the concentration–time curve (AUC) (i.e., quinolones) and peak levels (aminoglycosides) are the major parameters that correlate with efﬁcacy (Fig. 1). The ratio of peak concentration to MIC is a measure of potency that also indicates the efﬁcacy of the drug in these agents. With drugs that exhibit time-dependent killing and minimal-to-moderate persistent effects, time above MIC is the major parameter-determining efﬁcacy. Beta-lactam and macrolide antibiotics belong to this second group.

Figure 1 Predictors of bacterial eradication: pharmacokinetic/pharmacodynamic proﬁles.

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Studies in otitis media show that there appears to be a relationship between the time above MIC in serum and in middle ear ﬂuid (MEF) for beta-lactam antibiotics. It is predicted that to achieve at least 80% to 85% bacteriologic cure in otitis media, serum concentrations should exceed the MIC of pathogens for at least 40% of the dosing interval (42). For the same cure rate, the peak MEF to MIC ratio should be in the range of 3 to 6. If the MICs for pathogens are known, it will be possible to predict those agents for which adequate concentrations can be achieved. Despite substantial MEF concentrations, some drugs such as the macrolides (i.e., erythromycin, azithromycin and clarithromycin) are clinically less reliable against H. inﬂuenzae because the MICs for this organism frequently exceed the achievable MEF concentrations. In contrast, other drugs such as the oral third-generation cephalosporins (i.e., ceﬁxime, ceftibuten) that reach more modest absolute MEF concentrations, but have such low MIC90s for H. inﬂuenzae and M. catarrhalis may be more effective in eradicating this pathogen. However, these agents are ineffective against penicillin-resistant S. pneumoniae (41). Fluoroquinolones demonstrate concentration-dependent killing. The ratio of the peak concentration (Cmax) to the MIC and of the area under the curve (AUC) to the MIC appear to be the parameters that best correlate with clinical efﬁcacy. If the free-drug AUC/MIC ratio is >25–30, the probability of a favorable clinical outcome is quite high (>100%) for patients infected with gram-positive organisms (43). Using this cutoff criterion (AUC/MIC ratio, >25–30), ciproﬂoxacin fares poorly against gram-positive organisms, whereas gatiﬂoxacin, gemiﬂoxacin, levoﬂoxacin, and moxiﬂoxacin all exceed this threshold. However, levoﬂoxacin barely achieves the goal, and for isolates with MICs of 2.0 mg/mL, levoﬂoxacin is inadequate. PRINCIPLES OF THERAPY Selection of the appropriate agent(s) is generally made on an empirical basis, and the agents should be effective against any potential organisms that may cause the infection (44). In the empirical choice of antimicrobial therapy for sinuses, several balances between narrow- and wide-spectrum antimicrobial agents must be made. If the patient fails to show signiﬁcant improvement or shows signs of deterioration despite treatment, it is important to obtain a culture, preferably through sinus puncture, as this may reveal the presence of resistant bacteria. Further antimicrobial treatment is based, whenever possible, on results of the culture. Obtaining a culture through endoscopy is an alternative approach (45). However, the specimen may be contaminated with nasal ﬂora. Surgical drainage may be extremely important at that time. Culture of nasal pus or of sinus exudate obtained by rinsing through the sinus ostium can give unreliable information because of contamination by the resident bacterial nasal ﬂora.

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Table 7 Causes for Failure in the Treatment of Bacterial Sinusitis Viral infection Noncompliance Resistant organism(s) as a result of: Recent treatment with antibiotic agents Acquisition of resistant organisms (community, day care, school, or nosocomial) Emergence of resistance during therapy Inadequate penetration of antibiotics to site Lack of drainage (anatomical blockage or due to medication) Persistence of predisposing risk factors Impaired host defenses

Factors within the sinus cavity that may enable organisms to survive antimicrobial therapy are inadequate penetration of antimicrobial agents, a high protein concentration (can bind antimicrobial agents), a high content of enzymes that inactivate antimicrobial agents (i.e., beta-lactamase), decreased multiplication rate of organisms that interfere with the activity of bacteriostatic agents, and reduction in pH and oxygen partial pressure, which reduces the efﬁcacy of some antimicrobial agents (e.g., aminoglycosides and quinolones) (46) (Table 7). Failure to improve on completion of appropriate antibiotic therapy should prompt consideration of bacterial resistance, noncompliance, or complicated sinusitis. Antimicrobial agents that achieve good intrasinus concentrations can, however, fail to eradicate the pathogen(s) if there is impairment of local defenses (e.g., phagocytosis, ciliary motility) within the sinus environment. Treatment of Acute Sinusitis Amoxicillin can be appropriate for the initial treatment of acute uncomplicated mild sinusitis (Table 8). However, antimicrobials that are more effective against the major bacterial pathogens (including those that are resistant to multiple antibiotics) may be indicated (Table 9) as initial therapy and for the retreatment of those who have risk factors prompting a need for more

Table 8 Indications for Amoxicillin Therapy (high dose) Mild illness No history of recurrent acute sinusitis During summer months When no recent antimicrobial therapy has been used When patient has had no recent contact with patient(s) on antimicrobial therapy When community experience shows high success rate of amoxicillin

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Table 9 Recommended Antibacterial Agents for Initial Treatment of Acute Sinusitis or After No Improvement Factors prompting more effective antibioticsa

At diagnosis

No

High-dose amoxicillin

Yes

High-dose amoxicillin/ clavulanate or a ‘‘new’’ quinoloneb or telithromycinb or cefuroxime-axetil or cefdinir or cefpodoxime proxetil

a

Clinically treatment failure at 48–72 hr after starting treatment High-dose amoxicillin/ clavulanate or a ‘‘new’’ quinoloneb or telithromycinb or cefuroxime or cefdinir or cefpodoxime proxetil High-dose amoxicillin/ clavulanate or a ‘‘new’’ quinoloneb or telithromycinb or cefuroxime-axetil or cefdinir or cefpodoxime proxetil

See Table 7. Not approved for children (<18 years).

b

effective antimicrobials (Table 10) and those who had failed amoxicillin therapy. These agents include amoxicillin and clavulanic acid, the ‘‘newer’’ quinolones (e.g., levoﬂoxacin, gatiﬂoxacin, moxiﬂoxacin), telithromycin, and some second- and third-generation cephalosporins (cefdinir, cefuroxime-axetil, and cefpodoxime proxetil). These agents should be administered to patients when bacterial resistance is likely (i.e., recent antibiotic therapy, winter season, increased resistance in the community), the presence of a moderate to severe infection, the presence of comorbidity (diabetes, chronic renal, hepatic, or cardiac pathology), and when penicillin allergy is present (Tables 9 and 10). Agents that are less effective because of growing bacterial resistance may, however, be considered for patients with antimicrobial allergy. These include the macrolides, TMP-SMX, tetracyclines, and clindamycin (47). A number of antimicrobial agents have been studied in the therapy of acute sinusitis over the past 25 years, with the use of pre- and post-treatment aspirate cultures. Those studied were ampicillin, amoxicillin, amoxicillin– clavulanic acid, cefuroxime axetil, cefprozil, loracarbef, levoﬂoxacin, gatiﬂoxacin, moxiﬂoxacin, and gemiﬂoxacin. For a 10-day course of therapy, the success rate was a bacteriological cure over of 80% to 90%. Appropriate antibiotic therapy is of paramount importance, even though it is estimated that spontaneous recovery occurs in about half of patients (19,48).

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Table 10 Risk Factors Prompting a Need for More Effective Antimicrobialsa Bacterial resistance is likely Antibiotic use in the past month, or close contact with a treated individual(s) Resistance common in community Failure of previous antimicrobial therapy Infection in spite of prophylactic treatment Child in day care facility Winter season Smoker or smoker in family Presence of moderate to severe infection Presentation with protracted (>30 days) or moderate to severe symptoms Complicated ethmoidal sinusitis Frontal or sphenoidal sinusitis Patient history of recurrent acute sinusitis Presence of comorbidity and extremes of life Comorbidity (i.e., chronic cardiac, hepatic, or renal disease, diabetes) Immunocompromised patient Younger than two years of age or older than 55 years Allergy to penicillin Allergy to amoxicillin a Amoxicillin and clavulanic acid, second- and third-generation cephalosporins, telithromycin, and the ‘‘respiratory’’ quinolones.

Antimicrobial therapy is beneﬁcial and effective in the prevention of septic complications (48). The recommended length of therapy for acute sinusitis is at least 14 days or seven days beyond the resolution of symptoms, whichever is longer. However, no controlled studies have proved the length of therapy sufﬁcient to resolve the infection. Within the last two years, six panels of experts recently presented reviews and rendered their recommendations on how to diagnose and manage sinusitis (19,49–53). The recommendations of three of these guidelines are summarized in Chapter 10. Treatment of Chronic Sinusitis Many of the pathogens isolated from chronically inﬂamed sinuses are resistant to penicillins through the production of beta-lactamase (7,54). These include both aerobic (S. aureus, H. inﬂuenzae, and M. catarrhalis) and gram-negative bacilli anaerobic isolates (all B. fragilis and over half of the Prevotella, Porphyromonas, and Fusobacterium spp.). Retrospective studies illustrate the superiority of therapy effective against both aerobic and anaerobic BLPB in chronic sinusitis (54,55). Amoxicillin-clavulanate (54) or clindamycin (55), both effective against both aerobic and anaerobic bacteria, were superior to antimicrobials, but were not active against these organisms.

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The choice of antimicrobial agent in chronic sinusitis should provide coverage for the usual pathogens in acute sinusitis (e.g., S. pneumoniae, H. inﬂuenzae, and M. catarrhalis) as well as beta-lactamase–producing aerobic and anaerobic organisms. Therefore, treatment with a broadspectrum antibiotic that is stable against beta-lactamases and active against penicillin-resistant S. pneumoniae with anaerobic coverage may be optimal for the treatment of chronic sinusitis. Antimicrobial agents used for chronic sinusitis therapy should therefore be effective against both aerobic and anaerobic BLPB; these include the combination of a penicillin (e.g., amoxicillin) and a beta-lactamase inhibitor (e.g., clavulanic acid), clindamycin, chloramphenicol, the combination of metronidazole and a macrolide, and the ‘‘newer’’ quinolones (e.g., trovaﬂoxacin). All of these agents (or similar ones) are available in oral and parenteral forms. Other effective agents that are available only in parenteral form are some of the second-generation cephalosporins (e.g., cefoxitin, cefotetan and cefmetazole), combination of a penicillin (e.g., ticarcillin, piperacillin, ampicillin) and a beta-lactamase inhibitor (e.g., clavulanic acid, tazobactam, sulbactam), and the carbapenems (i.e., imipenem, meropenem). If aerobic gram-negative organisms such as P. aeruginosa are involved, parenteral therapy with an aminoglycosides, a fourth-generation cephalosporin (cefepime or ceftazidime), or oral or parenteral treatment with a ﬂuoroquinolone (only in postpubertal patients) is added. Parenteral therapy with a carbapenem (e.g., imipenem) is more expensive, but provides coverage for most potential pathogens, both anaerobes and aerobes. From a practical point of view, it is not generally recommended or necessary for clinicians to perform a culture for anaerobic bacteria in these patients. The tests are very expensive and timely, and most clinicians do not have access to materials that are necessary to properly culture anaerobic organisms. They should however, rely, on the data that have demonstrated the existence of anaerobes (discussed above) in chronic sinusitis. Culture for anaerobes should, however, be performed in those that do not respond to therapy and/or develope a complication. Clinicians should consider the anaerobic activity for the various antimicrobials before selecting an antibiotic agent for the treatment of chronic sinusitis. The length of therapy is at least 21 days, and may be extended up to 10 weeks. Fungal sinusitis can be treated with surgical debridement of the affected sinuses and antifungal therapy (56). In contrast to acute sinusitis, which is generally treated vigorously with antibiotics, many physicians believe that surgical drainage is the mainstay of therapy in chronic sinusitis. When the patient does not respond to medical therapy, the physician should consider surgical drainage. Impaired drainage may be a major contribution to the development of chronic sinusitis, and correction of the obstruction helps to alleviate the infection and prevent recurrence. The use of antimicrobial therapy alone, without surgical drainage of collected pus, may not result

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in clearance of the infection. The chronically inﬂamed sinus membranes with diminished vascularity may be a poor means of carrying an adequate antibiotic level to the infected tissue, even though the blood level may be therapeutic. Furthermore, the reduction in the pH and oxygen tension within the inﬂamed sinus may interfere further with the activity of the antimicrobial agents, which can result in bacterial survival despite a high antibiotic concentration (46). CONCLUSIONS Many of the organisms recovered from sinusitis are resistant to penicillins, either through the production of beta-lactamase (H. inﬂuenzae, M. catarrhalis, S. aureus, Fusobacterium spp., and Prevotella spp.) or through changes in the penicillin-binding protein (S. pneumoniae). The pathogenicity of betalactamase–producing bacteria is expressed directly through their ability to cause infections, and indirectly through the production of beta-lactamase. The indirect pathogenicity is conveyed not only by surviving penicillin therapy, but also by ‘‘shielding’’ penicillin-susceptible pathogens from the drug. The direct and indirect virulent characteristics of these bacteria require the administration of appropriate antimicrobial therapy directed against all pathogens in mixed infections. The oral antimicrobials that are the most effective in management of acute sinusitis are amoxicillin-clavulanate (given in a high dose), the newer quinolones (gatiﬂoxacin, moxiﬂoxacin) and the secondgeneration cephalosporins (cefuroxime, cefpodoxime, cefprozil, or cefdinir). The oral antimicrobials that are the most effective in management of chronic sinusitis are amoxicillin-clavulanate, clindamycin, and the combination of metonidazole and a penicillin.

REFERENCES 1. Brook I. Emergence and persistence of beta-lactamase-producing bacteria in the oropharynx following penicillin treatment. Arch Otolaryngol Head Neck Surg 1988; 114:667–670. 2. Brook I, Gober AE. Emergence of beta-lactamase-producing aerobic and anaerobic bacteria in oro-pharynx of children following penicillin chemotherapy. Clin Pediatr (Phila) 1984; 23:338–341. 3. Brook I, Gober AE. Monthly changes in the rate of recovery of penicillinresistant organisms from children. Pediatr Infect Dis J 1997; 16:255–256. 4. McCracken GH Jr. Considerations in selecting an antibiotic for treatment of acute otitis media. Pediatr Infect Dis J 1994; 13:1054–1057. 5. Brook I, Gober AE. Resistance to antimicrobials used for therapy of otitis media and sinusitis: effect of previous antimicrobial therapy and smoking. Ann Otol Rhinol Laryngol 1999; 108:645–647. 6. Brook I. The role of beta-lactamase-producing bacteria in the persistence of streptococcal tonsillar infection. Rev Infect Dis 1984; 6:601–607.

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7. Brook I, Yocum P, Frazier EH. Bacteriology and b-lactamase activity in acute and chronic maxillary sinusitis. Arch Otolaryngol Head Neck Surg 1996; 122:418–423. 8. Hackman AS, Wilkins TD. In vivo protection of Fusobacterium necrophorum from penicillin by Bacteroides fragilis. Antimicrob Agents Chemotherapy 1975; 7:698–703. 9. Brook I, Pazzaglia G, Coolbaugh JC, Walker RI. In vivo protection of group A beta-hemolytic streptococci by beta-lactamase producing Bacteroides species. J Antimicrob Chemother 1983; 12:599–606. 10. Brook I, Pazzaglia G, Coolbaugh JC, Walker RI. In vivo protection of penicillin susceptible Bacteroides melaninogenicus from penicillin by facultative bacteria which produce beta-lactamase. Can J Microbiol 1984; 30:98–104. 11. Simon HM, Sakai W. Staphylococcal anatagosim to penicillin group therapy of hemolytic streptococcal pharyngeal infection: effect of oxacillin. Pediatrics 1963; 31:463–469. 12. Scheifele DW, Fussell SJ. Frequency of ampicillin resistant Haemophilus parainﬂuenzae in children. J Infect Dis 1981; 143:495–498. 13. Brook I, Yocum P. In vitro protection of group A beta-hemolytic streptococci from penicillin and cephalothin by Bacteroides fragilis. Chemotheraphy 1983; 29:18–23. 14. Wald ER, Milmore GJ, Bowen AD, Ledema-Medina J, Salamon N, Bluestone CD. Acute maxillary sinusitis in children. N Engl J Med 1981; 304:749–54. 15. Mustafa E, Tahsin A, Mustafa O, Nedret K. Bacteriology of antrum in adults with chronic maxillary sinusitis. Laryngoscope 1994; 104:321–324. 16. Doern GV, Jorgensen JH, Thornsberry C, Preston DA, Tubert T, Redding JS, Maher LA. National collaborative study of the prevalence of antimicrobial resistance among clinical isolates of Haemophilus inﬂuenzae. Antimicrob Agents Chemother 1988; 32:180–185. 17. Jorgensen JH, Doern GV, Maher LA, Howell AW, Redding JS. Antimicrobial resistance among respiratory isolates of Haemophilus inﬂuenzae, Moraxella catarrhalis, and Streptococcus pneumoniae in the United States. Antimicrob Agents Chemother 1990; 34:2075–2080. 18. Jacobs MR. Worldwide trends in antimicrobial resistance among common respiratory tract pathogens in children. Pediatr Infect Dis J 2003; 22(suppl 8): S109–S1019. 19. Sinus and Allergy Health Partnership: Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Otolaryngol Head Neck Surg 2004; 130(suppl 1):1S. 20. Jacobs MR, Felmingham D, Appelbaum PC, Gruneberg RN, The Alexander Project Group. The Alexander Project 1998–2000: susceptibility of pathogens isolated from community-acquired respiratory tract infection to commonly used antimicrobial agents. J Antimicrob Chemother 2003; 52:229–246. 21. Dagan R, Johnson CE, McLinn S, Abughali N, Feris J, Leibovitz E, Burch DJ, Jacobs MR. Bacteriologic and clinical efﬁcacy of amoxicillin/clavulanate vs. azithromycin in acute otitis media. Pediatr Infect Dis J 2000; 19:95–104. 22. Doern GV. Antimicrobial resistance with Streptococcus pneumoniae: much ado about nothing? Semin Respir Infect 2001; 16:177–185. 23. Dominguez MA, Pallares R. Antibiotic resistance in respiratory pathogens. Curr Opin Pulmonary Med 1998; 4:173–179.

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24. Fung-Tomc JC, Huczko E, Stickle T, et al. Antibacterial activity of cefprozil compared with those of 13 oral cephems and 3 macrolides. Antimicrob Agent Chemother 1995; 39:533–538. 25. Jacobs MR, Bajaksouzian S, Zilles A, Lin GR, Pankuch GA, Appelbaum PC. Susceptibilities of Streptococcus pneumoniae and Haemophilus inﬂuenzae to 10 oral antimicrobial agents based on pharmacodynamic parameters: 1997 U. S. surveillance study. Antimicrob Agents Chemother 1999; 43:1901–1908. 26. Lynch JP III, Martinez FJ. Clinical relevance of macrolide-resistant Streptococcus pneumoniae for community-acquired pneumonia. Clin Infect Dis 2002 Mar 1; 34(suppl 1):S27–S46. 27. Klugman KP, Capper T, Widdowson CA, Koornhof HJ, Moser W. Increased activity of 16-membered lactone ring macrolides against erythromycin-resistant Streptococcus pyogenes and Streptococcus pneumoniae: characterization of South African isolates. J Antimicrob Chemother 1998; 42:729–734. 28. Granizo JJ, Aguilar L, Casal J, Dal-Re R, Baquero F. Streptococcus pneumoniae resistance to erythromycin and penicillin in relation to macrolide and b-lactam consumption in Spain (1979–1997). J Antimicrob Chemother 2000; 46:767–773. 29. Cizman M, Pokorn M, Seme K, Paragi A, Orazem A. Inﬂuence of increased macrolide consumption on macrolide resistance of common respiratory pathogens. Eur J Clin Microbiol Infect Dis 1999; 18:522–524. 30. Peterson LR. Quinolone molecular structure–activity relationships: what have we learned about improving antibacterial activity. Clin Infect Dis 2001; 33(suppl 3):S180–S186. 31. Pestova E, Beyer R, Cianciotto NP, Noskin GA, Peterson LR. Contribution of topoisomerase IV and DNA gyrase mutations in Streptococcus pneumoniae for resistance to novel ﬂuoroquinolones. Antimicrob Agents Chemother 1999; 43:2000–2004. 32. Lu T, Zhao X, Drlica K. Gatiﬂoxacin activity against quinolone-resistant gyrase: allele-speciﬁc enhancement of bacteriostatic and bactericidal activities by the C-8 methoxy group. Antimicrob Agents Chemother 1999; 43:2969–2974. 33. Scheld WM. Maintaining ﬂuoroquinolone class efﬁcacy: review of inﬂuencing factors. Emerg Infect Dis 2003; 9:1–9. 34. Saravolatz LD, Leggett J. Gatiﬂoxacin, gemiﬂoxacin, and moxiﬂoxacin: the role of 3 newer ﬂuoroquinolones. Clin Infect Dis 2003; 37(1):1210–1215. 35. Orden B, Perez Trallero E, Montes M, Martinez R. Erythromycin resistance of Streptococcus pyogenes in Madrid. Pediatr Infect Dis J 1998; 17:470–473. 36. Spangler SK, Jacobs MR, Pankuch GA, Appelbaum PC. Susceptibility of 170 penicillin-susceptible and -resistant pneumococci to six oral cephalosporins, four quinolones, desacetylcefotaxime, Ro 23–9424 and RP 67829. J Antimicrob Chemother 1993; 31:273–280. 37. Brook I, Gober AE. Resistance to antimicrobials used for therapy of otitis media and sinusitis: effect of previous antimicrobials therapy and smoking. Ann Otol Rhinol Laryngol 1999; 108:645–647. 38. Clark JP, Langston E. Ketolides: a new class of antibacterial agents for treatment of community-acquired respiratory tract infections in a primary care setting. Mayo Clin Proc 2003; 78:1113–1124. 39. Balfour JA, Figgitt DP. Telithromycin. Drugs 2001; 61:815–829.

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40. Phillips I, King A, Shannon K. Comparative in-vitro properties of the quinolones. In: Andriole VT, ed. The Quinolones. 3rd ed. San Diego: Academic Press, 2000:99–137. 41. Craig WA. Pharmacokinetic/pharmacodynamic parameters: rationale for antibacterial dosing of mice and men. Clin Infect Dis 1998; 26:1–10. 42. Craig WA, Andes D. Pharmacokinetics and pharmacodynamics of antibiotics in otitis media. Pediatr Infect Dis J 1996; 15:255–259. 43. Schentag JJ, Gilliland KK, Paladino JA. What have we learned from pharmacokinetic and pharmacodynamic theories? Clin Infect Dis 2001; 32(suppl 1): S39–S46. 44. Brook I, Frazier EH, Foote PA. Microbiology of the transition from acute to chronic maxillary sinusitis. J Med Microbiol 1996; 45:372–375. 45. Brook I, Frazier EH, Foote PA. Microbiology of chronic maxillary sinusitis: comparison between specimens obtained by sinus endoscopy and by surgical drainage. J Med Microbiol 1997; 46:430–432. 46. Carenfelt C, Eneroth CM, Lundberg C, Wretlind B. Evaluation of the antibiotic effect of treatment of maxillary sinusitis. Scand J Infect Dis 1975; 7: 259–264. 47. Gwaltney JM Jr. Acute community-acquired sinusitis. Clin Infect Dis 1996; 23:209–225. 48. Wald ER, Chiponis D, Leclesma-Medina J. Comparative effectiveness of amoxicillin and amoxicillin–clavulanate potassium in acute paranasal sinus infection in children: a double-blind, placebo-controlled trial. Pediatrics 1998; 77:795–800. 49. Spector SL, Bernstein IL. Parameters for the diagnosis and management of sinusitis. J Allergy Clin Immunol 1998; 102(suppl):S107–S144. 50. Williams JW Jr, Aguilar C, Makela M, Cornell J, Holleman D, Chiquette E, Simel DL. Antibiotics for acute maxillary sinusitis. 1:Cochrane Database Syst Rev 2000; (2):CD000243. 51. Benninger MS, Holzer SES, Lau J. Diagnosis and treatment of uncomplicated acute bacterial rhinosinusitis: summary of the agency for health care policy and research evidence-based report. Otolaryngol Head Neck Surg 2000; 122:1–7. 52. Brook I, Gooch WM III, Jenkins SG, Pichichero ME, Reiner SA, Sher L, Yamauchi T. Medical management of acute bacterial sinusitis. Recommendations of a clinical advisory committee on pediatric and adult sinusitis. Ann Otol Rhinol Laryngol 2000; 109:1–20. 53. Clinical Practice Guidelines: Managemement of Sinusitis. Pediatrics 2001; 108:798–807. 54. Brook I, Thompson DH, Frazier EH. Microbiology and management of chronic maxillary sinusitis. Arch Otolaryngol Head Neck Surg 1994; 120:1317–1320. 55. Brook I, Yocum P. Management of chronic sinusitis in children. J Laryngol Otol 1995; 109:1159–1162. 56. Decker CF. Sinusitis in the immunocompromised host. Curr Infect Dis Rep 1999; 1:27–32.

10 Medical Management of Acute Sinusitis Dennis A. Conrad Division of Infectious Diseases, Department of Pediatrics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, U.S.A.

INTRODUCTION The medical management of acute sinusitis remains problematic due to the inherent contradictions concerning diagnosis and treatment. Although a signiﬁcant number of upper respiratory tract infections (URTIs) requiring evaluation by health care providers occur annually, the ability to precisely distinguish bacterial sinusitis from viral rhinosinusitis by clinical criteria still does not exist. Even though the majority of cases of acute bacterial sinusitis will resolve spontaneously without speciﬁc anti-infective therapy, antimicrobial treatment shortens the duration of illness and lessens the severity of symptoms. An increasing prevalence of respiratory pathogens resistant to traditionally prescribed antibiotics has been documented during the last decade, yet standard antibacterial regimens still result in acceptably high cure rates despite probable microbial resistance in vitro. Current opinion on the management of acute bacterial sinusitis embracing the principles of best practice is to establish the diagnosis of acute bacterial sinusitis as accurately as is possible by utilizing clinical information, and to prescribe and treat the patient with an antibiotic chosen for predicted probability of success and reduced potential for selection of antimicrobial resistance (1). In addition, several important analyses of the management of acute sinusitis have been published within the last seven years that speciﬁcally address the evidentiary basis for best clinical practices; synthesis of

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this information provides the framework for the management recommendations contained in this chapter. As has been true for previously published recommendations, these current recommendations will arise from interpretation of results achieved in clinical trials and from best estimates where deﬁnitive information is lacking.

RATIONALE FOR THE RECOMMENDED MANAGEMENT OF ACUTE BACTERIAL SINUSITIS American Academy of Pediatrics The principles for the judicious use of antimicrobial agents that should be used to treat acute sinusitis in children were published in 1998 (2). The authors recommended that the clinical diagnosis of acute bacterial sinusitis in children required the presence of mild nonspeciﬁc symptoms and signs of URTI, such as purulent rhinitis or cough, which persisted for 10 to 14 days, or the presence of more severe symptoms and signs, such as high fever and facial fullness or pain, which were more speciﬁc for sinus mucosal inﬂammation. The diagnosis of acute sinusitis should be based on clinical ﬁnding; the use of radiographic evaluation was to be limited to episodes of recurrent sinus disease, when complications of acute sinusitis were suspected, or if the presumptive clinical diagnosis of bacterial sinusitis was in doubt. Amoxicillin was appropriate for the initial treatment of acute uncomplicated sinusitis, whereas a b-lactamase-stable b-lactam antibiotic would be appropriate to treat recurrent infection and amoxicillin therapeutic-failures. These recommendations remain useful to date as a guide for current clinical practice.

American Academy of Allergy and Clinical Immunology Comprehensive practice parameters on sinusitis addressing diagnosis, antimicrobial therapy, and adjunctive treatments were published in 1998 (3). Selected conclusions were that diagnosis of bacterial sinusitis should be established by a combination of clinical history with physical examination, nasal cytology, and/or imagining studies, that antibiotics were the primary therapy for bacterial sinusitis, and that treatment choice should be based on predicted effectiveness, costs, and potential adverse drug effects. Critical analyses of the use of the adjunctive therapies of antihistamines, a-adrenergic decongestants, topical and systemic glucocorticosteroids, saline lavage, mucolytics, expectorants, and nasal endoscopic surgical intervention were also provided and detailed to a degree that merits speciﬁc attention in terms of current clinical practice as regards the non-antibiotic-therapy aspects of disease management (Table 1).

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Table 1 Adjunctive Therapy in the Management of Acute Sinusitis Adjunctive therapy

Evidence for efﬁcacy

Antihistamines

None in acute sinusitis

a-Adrenergic decongestants Topical glucocorticosteroids Systemic glucocorticosteroids

Prospective studies absent

Saline lavage,mucolytics, expectorants Nasal endoscopy

No conﬁrmation of speciﬁc efﬁcacy

Useful in reducing mucosal inﬂammation and edema Not adequately studied

Subjective improvement in patients undergoing procedure

Potential utility Chronic sinusitis associated with allergic rhinitis May reduce mucosal edema and improve ostial patency Treatment of rhinitis accompanying sinusitis Topical agents preferred due to reduced risk of adverse drug effects Wetting agents may provide symptomatic relief Useful for recurrent sinusitis due to ostial obstruction

Source: From Ref. 3.

Agency for Health Care Policy and Research In 1999, the Agency for Health Care Policy and Research published a comprehensive analysis of medical literature evidence concerning the diagnosis and treatment of community-acquired acute bacterial rhinosinusitis in children and adults (4). Utilizing a MEDLINE search of human studies of sinusitis published between 1966 and May 1998, meta-analyses were performed to evaluate clinical management strategies. Of the eight research questions posed and subsequently answered by the review, the observations pertaining to four of the questions are particularly germane to the current medical management of acute sinusitis (Table 2). The authors of the report concluded that either symptomatic treatment or the use of clinical criteria to select patients to be treated with antibiotics were the most cost-effective strategies to manage patients with uncomplicated acute bacterial sinusitis, and that the use of either amoxicillin or trimethoprim– sulfamethoxazole should be the initial therapeutic consideration due to probable efﬁcacy, adverse events proﬁles, and treatment cost. Subcommittee on Management of Sinusitis and the Committee on Quality Improvement Due to the limited number of randomized studies of acute bacterial sinusitis evaluated by the Agency for Health Care Policy and Research, the Subcommittee on Management of Sinusitis and the Committee on Quality

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Table 2 Results of Meta-Analysis Evaluating Management of Acute Sinusitis I. What are the values of clinical criteria and imaging for diagnosis of acute bacterial sinusitis? A. Clinical criteria may have a diagnostic equivalence to sinus radiography. II. Are antibiotics effective in resolving the symptoms of acute bacterial sinusitis? A. Approximately 67% of patients receiving placebo recovered without antibiotic therapy. B. Antibiotic therapy increased the number of patients cured and shortened the duration of symptoms. III. What is the efﬁcacy and safety of antibiotics in treatment of acute bacterial sinusitis? A. Antibiotic treatment reduced the clinical failure rate by one-half when compared to placebo. B. Amoxicillin and trimethoprim–sulfamethoxazole were as effective as newer and more expensive antibiotics. C. Approximately 4% of patients receiving amoxicillin had adverse effects causing cessation of therapy; no statistical difference in this percentage was observed for patients receiving other antibiotics. IV. Do ancillary therapies beneﬁt the treatment of acute bacterial sinusitis? A. Difference in the design of individual studies prevented independent analysis of the beneﬁt of decongestants, antihistamines, topical and systemic steroids, and surgical drainage and irrigation. Source: From Ref. 4.

Improvement of the American Academy of Pediatrics partnered with the Agency for Health Care Policy and Research and family practice and otolaryngology colleague organizations to provide a supplement speciﬁcally for the management of acute bacterial sinusitis in children. Utilizing information gleaned from nonrandomized pediatric treatment trials that were published between 1966 and March 1999, in conjunction with the randomized trials that had been reviewed during the Agency for Health Care Policy and Research study, a technical report (5) and a clinical practice guideline for the management of sinusitis pertinent to childhood infections (6) were generated and published in 2001. Of the four clinical practice guideline recommendations that were formulated following review of these additional studies, three of these recommendations speciﬁcally address the medical management of acute bacterial sinusitis occurring in children (Table 3). International Journal of Pediatric Otorhinolaryngology Consensus Opinion A consensus opinion that was published in 1999 concerning the management of rhinosinusitis in children is noteworthy for providing recommendations concerning the place for surgery in the management of sinusitis (7).

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Table 3 Management of Acute Sinusitis in Children The diagnosis of acute bacterial sinusitis in children is clinical, and is based on either persistence or severity of upper respiratory tract symptoms. Imaging studies are not necessary to conﬁrm a clinical diagnosis of sinusitis; computed tomography of the paranasal sinuses should be reserved for preoperative evaluation. Antibiotic therapy is recommended for management of acute bacterial sinusitis; no recommendations can be made concerning adjuvant therapies, antimicrobial prophylaxis to prevent recurrent infection, and the use of complementary or alternative medicine to treat or prevent sinusitis. Source: From Ref. 6.

The recommended uses of adenoidectomy and antral lavage were limited to selected cases that could not be characterized as uncomplicated acute bacterial sinusitis, and recommendations concerning the absolute and possible indications for endoscopic sinus surgery were provided (Table 4). American College of Radiology The American College of Radiology developed appropriateness criteria for the evaluation of sinusitis in the pediatric population that were published in 1999 (8). The recommendations that were contained in the report provided useful guidance concerning the selective use of imaging studies in the management of acute sinusitis (Table 5).

Table 4 Indications for Surgery in the Management of Acute Sinusitis Absolute indications Complete nasal obstruction in cystic ﬁbrosis patients Antrachoanal polyp Intracranial complication Mucocele/mucopyocele Orbital abscess Traumatic injury of optic canal Dacryocystorhinitis resistant to medical therapy Fungal sinusitis Meningoencephalocele Neoplasm Source: From Ref. 7.

Possible indications Persistence of chronic rhinosinusitis failing medical management

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Table 5 Use of Radiographic Evaluation in the Management of Acute Sinusitis The diagnosis of acute and chronic sinusitis is based on clinical ﬁnding and not solely on the basis of imaging studies. Imaging studies are not indicated for successfully treated acute sinusitis. Coronal cranial computed tomography should be done if the symptoms of acute sinusitis persist beyond 10 days of appropriate therapy, and in cases of chronic sinusitis where imaging evaluation is desired. Plain radiography in the evaluation of sinusitis is generally unwarranted. Source: From Ref. 8.

Sinus and Allergy Health Partnership (2000) In 2000, the Sinus and Allergy Health Partnership published evidence-based recommendations for the diagnosis and treatment of acute bacterial rhinosinusitis (9). Based on acknowledged limited information available concerning comparative clinical trials evaluating diagnostic criteria and antibiotic choices for the management of sinusitis, the partnership recommended that the diagnosis of disease was clinical and could be based on the persistence of upper respiratory tract symptoms that did not improve after a 10-day duration or worsened during a ﬁve to seven-day interval. Recommended treatment of adult patients with mild disease who were not exposed to antibacterial therapy in the prior four to six weeks were amoxicillin (lower dose), amoxicillin/clavulanate, cefpodoxime, or cefuroxime. Adult patients with mild disease who had been exposed to antibacterials within the prior four to six weeks and those patients with moderate disease should be treated with amoxicillin (higher dose), amoxicillin/clavulanate, cefpodoxime, or cefuroxime. Adult patients with moderate disease who had been exposed to antibacterials within the prior four to six weeks should be treated with amoxicillin/ clavulanate, gatiﬂoxacin, levoﬂoxacin, moxiﬂoxacin, or a combination of either amoxicillin or clindamycin with either cefpodoxime or ceﬁxime. Recommendations for children with sinusitis paralleled those recommendations for adult patients, both in terms of prior antibiotic exposure and severity of disease, with the exception of exclusion of use of ﬂuoroquinolones in this pediatric population. The sinusitis management recommendations offered by the partnership were based on predicted efﬁcacy rates that had been mathematically calculated using in vitro susceptibility data, mechanisms of bacterial killing characteristics for the different antibacterial classes, and predicted pharmacokinetics of the individual drugs. Limited clinical trail results were available that could actually substantiate many of the recommendations, although a concern for the increased prevalence of bacteria which caused URTIs and were resistant to amoxicillin and trimethoprim–sulfamethoxazole prompted recommendations to consider broader-spectrum antimicrobials for initial therapy.

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Clinical Advisory Committee on Pediatric and Adult Sinusitis A clinical advisory committee on pediatric and adult sinusitis also published recommendations for the medical management of acute bacterial sinusitis in 2000 (10). This committee evaluated the importance of individual variables of patient history, clinical assessment, and diagnostic tests for the initial diagnosis of acute sinusitis. The elements of the patient history that were deemed signiﬁcantly important to establish the diagnosis of bacterial sinusitis were a ‘‘cold’’ that had been present for more than 7 to 10 days, ‘‘unusually’’ severe upper respiratory tract complaints, fever, mucopurulent discharge of greater than seven-days duration, pain referred to maxillary teeth, and no appreciable response to decongestant therapy. Signiﬁcantly important clinical ﬁndings were facial and midface tenderness, the appearance of the nasal mucosal surface, intranasal pus, and the presence of purulent postnasal mucus in the pharynx. Of the diagnostic tests evaluated, only anterior rhinoscopy, direct aspiration of the sinus, and bacterial cultures of aspirated material following sinus puncture were considered signiﬁcantly important, with the latter two procedures limited to speciﬁc indications. Antimicrobial therapy recommendations were ranked in a tripartite hierarchy; agents of ﬁrst choice were amoxicillin and trimethoprim– sulfamethoxazole and second-line agents included cefpodoxime, cefprozil, cefuroxime, cefdinir, and amoxicillin–clavulanate. Recommended third-line agents were azithromycin, clarithromycin, ciproﬂoxacin, levoﬂoxacin, gatiﬂoxacin, moxiﬂoxacin, and clindamycin. In terms of adjunctive therapies, the committee endorsed the restricted use of topical decongestants limited to three days, and the use of systemic decongestants in adult patients. The committee acknowledged that the optimum management of acute sinusitis was controversial, but that the primary care physician should recognize the condition and treat aggressively due to disease impact on the quality of life for patients with active disease. American College of Physicians—American Society for Internal Medicine The American College of Physicians—American Society for Internal Medicine published clinical practice guidelines in 2001 that outlined the principles of appropriate antibiotic use to treat acute sinusitis occurring in adults (11); background information that supported these recommendations was published at the same time (12). Three recommendations concerning management of acute sinusitis were offered: sinus radiography is not recommended for the diagnosis of uncomplicated sinusitis; acute bacterial sinusitis does not require antibiotic

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treatment, especially when symptoms are either mild or moderate; and patients with severe symptoms or those with persistent moderate symptoms who have speciﬁc ﬁnding of bacterial infection should receive anti-infective therapy, preferentially with a narrow-spectrum agent (11). The companion article provided the rationale that supported the three recommendations contained in the clinical guidelines, and further observed that analgesia was an important aspect of management of acute sinusitis and that topical and oral decongestants may ameliorate some of the nasal symptoms associated with infection (12). Sinus and Allergy Health Partnership (2004) In 2004, the Sinus and Allergy Health Partnership published antimicrobial treatment guidelines for acute bacterial rhinosinusitis (13) that updated the original that were published in 2000 (9). The more recent guidelines largely reﬂected those of the original publication; the areas of signiﬁcant update included diagnostic modalities, contemporary antibacterial susceptibility proﬁles, addition of newer antimicrobial agents as recommended therapy, and expansion of the various pharmacodymanic/pharmacokinetic principles and therapeutic outcomes model (14) used to predict potential success of the individual agents. The anti-infective agents recommended for use to treat pediatric and adult patients with mildly symptomatic sinusitis who had not been exposed to an antibiotic in the preceding four to six weeks were amoxicillin, amoxicillin– clavulanate, cefpodoxime, cefuroxime, and cefdinir. Treatment options for those adult patients with mild sinusitis who had been exposed to an antibiotic in the previous four to six weeks and those adult patients with moderately symptomatic sinusitis were gatiﬂoxacin, levoﬂoxacin, moxiﬂoxacin, amoxicillin– clavulanate, ceftriaxone, or a combination of either amoxicillin or clindamycin and either ceﬁxime or rifampin. Treatment options for those pediatric patients with mild sinusitis who had been exposed to an antibiotic in the previous four to six weeks and those pediatric patients with moderately symptomatic sinusitis were amoxicillin– clavulanate, cefpodoxime, cefuroxime, cefdinir, ceftriaxone, or a combination of either amoxicillin or clindamycin and either ceﬁxime or rifampin. Summary of Varying Recommendations for the Management of Acute Bacterial Sinusitis Despite subtle variations in the recently published recommendations for the management of acute bacterial sinusitis, consistent principles are apparent. The diagnosis of acute bacterial sinusitis should be made after consideration of the presence and persistence of symptoms and signs of an URTI without the use of radiographic or microbiologic evaluation for the majority of patients, those antimicrobial agents most commonly used to treat respiratory

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tract infections are also generally effective in the treatment of acute bacterial sinusitis as evidenced by clinical trials and treatment experience, selected adjunctive medicinal therapies may improve symptoms but are not critical to achieve successful outcome, and surgical intervention is appropriately restricted to complicated infections. Therefore, current recommendations for the management of acute bacterial sinusitis may legitimately be an extension of recent prior recommendations generated by individual investigators, health care partnerships, and consensus of medical experts on behalf of practitioners, professional societies, and governmental agencies. CURRENT RECOMMENDATIONS FOR THE MANAGEMENT OF ACUTE BACTERIAL SINUSITIS Symptomatic Treatment of URTIs Children and adults who have a viral URTI may beneﬁt from symptomatic therapy, largely to improve the quality of life during the acute illness. The use of normal saline as a spray or lavage may provide symptomatic improvement by liquefying secretions to encourage drainage. The short-term (threeday) use of topical a-adrenergic decongestants can also provide symptomatic relief, but use should be restricted to older children and adults due to the potential for undesirable systemic effects in infants and young children. Topical glucocorticosteroids may also be useful in reducing nasal mucosal edema, especially in those cases where a patient who has seasonal allergic rhinitis develops the complication of an acute URTI. The antipyretic and analgesic effects of nonsteroidal anti-inﬂammatory agents may relieve or ameliorate the associated symptoms of fever, headache, generalized malaise, and facial tenderness. Until the clinical diagnosis of acute bacterial sinusitis is established, management of an URTI should be restricted to either no therapy or symptomatic care alone. Moreover, symptomatic care may prove useful in the management of acute bacterial sinusitis as adjunctive therapy, but no adjunct has been shown essential in improving the outcome achieved by antimicrobial therapy or effective in preventing the development of acute bacterial sinusitis in persons who have a viral URTI or allergic rhinitis. Clinical Diagnosis of Acute Bacterial Sinusitis The presence and persistence of mucopurulent nasal drainage for a minimum duration of time in a person who has an URTI is the most consistent feature that can establish the diagnosis of acute bacterial sinusitis by clinical criteria. An adult or a child who has an URTI and who also has persistent mucopurulent nasal drainage that has not improved during a symptomatic course of 10-days duration may be considered to have acute bacterial sinusitis for the purposes of initiating anti-infective therapy (Fig. 1).

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Figure 1 Diagnosis and initial management of acute sinusitis.

The presence of associated symptoms and signs that are suggestive of sinus mucosal inﬂammation further supports the clinical diagnosis of acute bacterial sinusitis. Unilateral or bilateral midfacial tenderness or maxillary pain, the subjective sensations of facial fullness or nasal congestion, fever, a persistent cough worsening when the patient is supine, maxillary or periorbital swelling, postnasal drainage, headache, and hyposmia or anosmia are symptoms and signs that are often associated with acute bacterial sinusitis. In those children and adults who have an URTI and who also have localizing symptoms and signs of sinus mucosal inﬂammation, the diagnosis of acute bacterial sinusitis may be made with reasonable certainty if those localized ﬁndings are present on the seventh day of symptoms of an URTI as measured from the time of initial onset. Radiographic Diagnosis of Acute Bacterial Sinusitis Radiographic evaluation of uncomplicated acute bacterial sinusitis is unnecessary to conﬁrm the clinical diagnosis or direct antimicrobial therapy. Imaging studies should be restricted to patients with symptoms and signs of URTI who appear acutely ill and in whom the diagnosis of acute bacterial sinusitis is

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unclear, patients who have evidence of having an intracranial or intraorbital complication of acute bacterial sinusitis, patients who fail to respond appropriately despite broad-spectrum antimicrobial therapy, patients with recurrent or chronic sinusitis, and for assessment in anticipation of endoscopic sinus surgery. In these special circumstances, coronal sinus computed tomography is the evaluation of choice. Antimicrobial Therapy Amoxicillin and trimethoprim–sulfamethoxazole still remain the most costeffective antimicrobial agents for the initial treatment of acute bacterial sinusitis. Recent analyses of the appropriate management of acute bacterial sinusitis have acknowledged the concern for the increasing prevalence of bacterial resistance to antimicrobial agents. This increased antibacterial resistance would have a potentially negative impact on reducing the clinical efﬁcacy of amoxicillin or trimethoprim–sulfamethoxazole, so recent therapeutic recommendations for treatment of acute bacterial sinusitis have been expanded to include amoxicillin/clavulanate, cefpodoxime, cefuroxime, cefdinir, and, for adult patients, ceftidoren, gatiﬂoxacin, levoﬂoxacin, and moxiﬂoxacin (Table 6). If the patient has a history of signiﬁcant allergy to b-lactam antibiotics and is not a candidate for ﬂuoroquinolone therapy, Table 6 Antibacterial Regimens for Treatment of Acute Sinusitis Antibiotic

Pediatric regimen

Amoxicillin 90 mg/kg/day bid Amoxicillin/clavulanate ES-600 90 mg amoxicillin/kg/day bid Amoxicillin/clavulanate XL – Cefdinir 14 mg/kg/day qd-bid Ceﬁxime 8 mg/kg/day qd-bid Cefpodoxime 10 mg/kg/day bid Ceftibuten 9 mg/kg/day qd Ceftidoren – Cefuroxime 30 mg/kg/day bid Azithromycin 10 mg/kg/day qd Clarithromycin 15 mg/kg/day bid Telithromycin – Clindamycin 20 mg/kg/day tid-qid Gatiﬂoxacin – Gemiﬂoxacin – Levoﬂoxacin – Moxiﬂoxacin – Trimethoprim/sulfamethoxazole 12 mg/60 mg/kg/day bid

Adult regimen 3.5 gm/day bid – 4 gm/day bid 600 mg/day qd-bid 400 mg/day qd-bid 400 mg/day bid 400 mg/day qd 800 mg/day bid 2 gm/day bid 500 mg/day qd 1 gm/day bid 800 mg/day qd 1.8 gm/day tid-qid 400 mg/day qd 320 mg/day qd 500 mg/day qd 400 mg/day qd 320 mg/1.6 gm/day bid

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then azithromycin or clarithromycin has been proposed as alternative choices. Even though these recommendations have been validated by different mathematical and therapeutic models that have been used to predict the relative efﬁcacy of these newer antibiotics, no clinical study has yet been performed that demonstrates the superiority of the extended-spectrum antimicrobials for the treatment of acute bacterial sinusitis due to penicillinresistant Streptococcus pneumoniae and b-lactamase-producing Haemophilus inﬂuenzae and Moraxella catarrhalis. Therefore, a reasonable approach to management would be an initial use of amoxicillin in higher dose or trimethoprim–sulfamethoxazole for penicillin-allergic patients, reserving the use of extended-spectrum antimicrobial agents to those patients who fail initial therapy (Fig. 2). Patients who have failed initial amoxicillin or trimethoprim– sulfamethoxazole therapy should be treated with an extended-spectrum antibiotic. If no appreciable improvement in symptoms has been noted after three days of the initial therapy, an anti-infective agent with an enhanced antibacterial spectrum should be substituted. For pediatric patients, amoxicillin/ clavulanate, cefpodoxime, cefuroxime, or cefdinir would be a reasonable choice. These antimicrobials would also be appropriate for adult patients who have failed initial therapy; in addition, ceftidoren, telithromycin, gatiﬂoxacin, gemiﬂoxacin, levoﬂoxacin, and moxiﬂoxacin could also be used. In time, ﬂuoroquinolone antibiotics approved for use in adults may also be approved by the United States Food and Drug Administration for use in children; until then, however, use in pediatric patients should be restricted to unusual and special circumstances. Patients who failed initial antimicrobial therapy and who have an inadequate response to an extended-spectrum antimicrobial may be managed either medically or surgically. Medical management would be by use of an antibiotic regimen that would incorporate those agents with the greatest activity in vitro against antibiotic-resistant respiratory bacteria. Ceftriaxone, parenterally administered daily or on alternative days until clinical resolution of illness, would be one anti-infective option. The second option would be a combination of two orally administered antibiotics chosen to maximize activity against gram-positive and -negative bacteria. Clindamycin, in combination with either ceﬁxime or ceftibuten, would be an appropriate regimen. A third option for pediatric patients could be the use of a ﬂuoroquinolone antimicrobial; with appropriate informed consent and parent approval, the failure of two successive antibacterial regimens may be a special circumstance justifying use of an agent otherwise currently unapproved for use in children. The duration of antimicrobial treatment of acute bacterial sinusitis should be for 10 days under most circumstances, as predicated on appreciable clinical improvement by the third treatment day. This recommendation could be modiﬁed as the continuation of treatment for seven days beyond

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Figure 2 Algorithm for antimicrobial and surgical management of acute sinusitis.

that time where substantial improvement in symptoms following therapy initiation ﬁrst occurred. One antibiotic, azithromycin, has been approved as a three-day regimen for treatment of acute bacterial sinusitis. However, due to a spectrum of antibacterial activity against the major pathogens

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causing acute bacterial sinusitis that is reduced when compared to b-lactam antibiotics and ﬂuoroquinolones, and despite the apparently more favorable ‘‘short-course’’ treatment duration, use of azithromycin should be restricted to those patients having a history of signiﬁcant allergy to penicillin and cephalosporin antibiotics and for whom use of a ﬂuoroquinolone would be inappropriate.

Use of Surgery in the Management of Acute Bacterial Sinusitis Endoscopic sinus surgery for aspiration of sinus contents for culture and susceptibility testing to guide anti-infective therapy could also be an option for patients who failed initial antimicrobial therapy and who had an inadequate response to an extended-spectrum antibiotic. A secondary beneﬁt may be achieved by endoscopically directed sinus irrigation. Although no evidence would suggest that this intervention is necessary to achieve successful outcome, many patients will perceive an immediate improvement in the severity of the symptoms of sinusitis following irrigation. Endoscopic sinus surgery generally has no place in the management of uncomplicated acute bacterial sinusitis and should be reserved for patients who have had a complicated course, such as the failure of medical management that was elucidated previously. As well, two additional circumstances may also justify endoscopic sinus surgery in the management of acute bacterial sinusitis. If a person with an episode of acute bacterial sinusitis has a history of frequent episodes of recurring sinusitis, endoscopic sinus surgery performed to identify a mechanical obstruction prohibiting appropriate sinus drainage may allow surgical correction to prevent subsequent recurrences. As well, when acute sinusitis occurs in an immunoincompetent host, knowledge of the infecting pathogen best obtained by ﬁberoptic sinus endoscopy and aspiration/ lavage can assist in selecting the appropriate anti-infective regimen. However, even for immunoincompetent hosts, ‘‘common things happen commonly;’’ a reasonable alternative would be to restrict endoscopic sinus surgery to those immunoincompetent hosts with acute sinusitis who failed initial empiric medical management. REFERENCES 1. Conrad DA, Jenson HB. Management of acute bacterial rhinosinusitis. Curr Opin Pediatr 2002; 14:86–90. 2. O’Brien KL, Dowell SF, Schwartz B, Marcy SM, Phillips WR, Gerber MA. Acute sinusitis—principles of judicious use of antimicrobial agents. Pediatrics 1998; 101:174–177. 3. Spector SL, Berstein IL, Li JT, Berger WE, Kaliner MA, Schuller DE, BlessingMoore J, Dykewicz MS, Fineman S, Lee RE, Nicklas RA. Sinusitis practice parameters. J Allergy Clin Immunol 1998; 102(suppl 6, Part 2):S107–S144.

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4. Agency for Health Care Policy and Research: Diagnosis and Treatment of Acute Bacterial Rhinosinusitis. AHCPR Evidence Report/Technology Assessment, Number 9, March 1999 (Rockville, MD). 5. Ioannidis JPA, Lau J. Technical Report: Evidence for the Diagnosis and Treatment of Acute Uncomplicated Sinusitis in Children: A Systemic Overview. Pediatrics 2001; 108(3). URL:http://www.pediatrics.org/cgi/content/full/ 108/3/e57. 6. American Academy of Pediatrics Subcommittee on Management of Sinusitis and Committee on Quality Improvement. Clinical Practice Guideline: Management of Sinusitis. Pediatrics 2001; 108:798–808. 7. Clement PAR, Bluestone CD, Gordts F, Lusk RP, Otten FWA, Goossens H, Scadding GK, Takahashi H, van Buchem L, van Cauwenberge P, Wald ER. Management of rhinosinusitis in children. Int J Pediatr Otorhinolaryngol 1999; 49(suppl 1):S95–S100. 8. Expert Panel on Pediatric Imaging. Sinusitis in the pediatric population. ACR Appropriateness Criteria, Reston, VA: American College of Radiology, 1999. 9. Sinus and Allergy Health Partnership: Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Otolaryngol Head Neck Surg 2000; 123(suppl 1, Part 2):S1–S32. 10. Brook I, Gooch WM, Jenkins, SG, Pichichero ME, Reiner SA, Sher L, Yamauchi T. Medical management of acute bacterial sinusitis: recommendations of a clinical advisory committee on pediatric and adult sinusitis. Ann Otol Rhinol Laryngol 2000; 109:2–20. 11. Snow V, Mottur-Pilson C, Hickner JM. Principles of appropriate antibiotic use for acute sinusitis in adults. Ann Intern Med 2001; 134:495–497. 12. Hickner JM, Bartlett JG, Besser RE, Gonzales R, Hoffman JR, Sande MA. Principles of appropriate antibiotic use for acute rhinosinusitis in adults: background. Ann Intern Med 2001; 134:498–505. 13. Sinus and Allergy Health Partnership: Antimicrobial treatment guidelines for acute bacterial rhinosinusitis. Otolaryngol Head Neck Surg 2004; 130(suppl 1): 1S–45S. 14. Poole MD. A mathematical therapeutic outcomes model for sinusitis. Otolaryngol Head Neck Surg 2004; 130(suppl 1):45S–46S.

11 Medical Management of Chronic Rhinosinusitis Alexander G. Chiu Division of Rhinology, Department of Otorhinolaryngology—Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.

Daniel G. Becker Department of Otorhinolaryngology—Head and Neck Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.

Sinusitis is one of the most common health problems in the United States, and accounts for health expenditures in billions of dollars per year. Although acute sinusitis accounts for the majority of these cases, it is estimated that chronic rhinosinusitis (CRS) results in 18 to 22 million U.S. physician ofﬁce visits annually (1) and causes signiﬁcant physical, emotional, and functional impairments (2). The exact etiology of CRS is still unknown, and therefore a clear deﬁnition and uniform treatment guidelines have not always been agreed upon. What has come to be known is that CRS represents a cycle of infection and inﬂammation. Therapy that fails to address both of these aspects may lead to inadequate results. There are currently multiple medications and delivery methods that are used in the medical management of CRS, and a combination of these therapies is needed in order to manage the multiple factors involved in the disease state. Before describing the current medical therapy, we will review the current working deﬁnition of CRS and its known inciting factors.

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DEFINITION OF CRS The Sinus and Allergy Health Partnership convened a multidisciplinary task force to develop deﬁnitions for CRS that would allow clinicians and researchers to accurately diagnose this condition. Their ﬁrst publication was in 1997 and the deﬁnitions were later revised in 2003 (3). The task force deﬁned CRS as the duration of symptoms for greater 12 consecutive weeks or greater 12 weeks of physical ﬁndings. Symptoms include nasal drainage, fatigue, post-nasal drainage, nasal obstruction, and facial pressure. Physical ﬁndings are erythema and/or edema of the middle meatus by nasal endoscopy, discolored nasal drainage or polyps, and/or abnormal ﬁndings on CT or plain sinus radiographs (3). The criteria not only rely on the duration of symptoms, but also on the objective evidence of inﬂammation within the sinonasal passages. Inﬂammation can be brought on by a variety of inciting factors. INCITING FACTORS IN SINUSITIS The most common causes of acute rhinosinusitis are preceding viral upper respiratory tract infections and inhalant allergies (4). Both of these inciting factors result in nasal mucosal edema and resultant blockage of the ostiomeatal complex, a functional area in which the anterior ethmoid, frontal, and maxillary sinuses drain. This physical obstruction may lead to hypo-oxygenation of the sinuses and impairment of the mucosal ciliary function. This results in a stasis of secretions that serves as an ideal environment for bacterial invasion. The distinction between acute and chronic sinusitis is made on the length of symptoms and signs of inﬂammation. The exact etiology behind CRS is yet unknown, but potential theories have ranged from inadequately treated acute bacterial infections to native fungus (5) and/or superantigens of colonizing bacteria (6). Regardless of cause, the ﬁnal common pathway is impaired clearance of secretions, damage to the mucosal lining with resultant ﬁbrosis and thickening of the lamina propria (7), and marked tissue eosinophilia (8). Eosinophilic inﬂammation results in activation of damaging cytokines and factors to the mucosa, and may result in an end pathway of nasal polyps and hypertrophic mucosa. A cycle then develops, as greater mucosal edema and obstruction lead to stasis of secretions and a greater growth of bacteria, which in turn can perpetuate the inﬂammatory response. To break this cycle of infection and inﬂammation, the ideal medical management is made by a combination of therapies aimed at reducing mucosal inﬂammation, promoting drainage of the sinuses and the release of secretions, and eradicating the inciting bacterial and/or fungal organisms. ANTIMICROBIAL THERAPY The organisms recovered from chronically inﬂamed sinuses are different from those of acute infections. While Streptococcus pneumoniae and

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Haemophilus inﬂuenzae are the most common isolates in acute sinusitis (9,10), polymicrobial ﬂora are present in CRS, which includes both aerobic and anaerobic bacteria. The predominant aerobic isolates include Staphylococcuys aureus, coagulase-negative staphylococci, and aerobic gram-negative bacteria such as Pseudomonas aeruginosa and Stenotrophomonas maltophilia. Anaerobic bacteria also play a prominent role in CRS. The recovery of these organisms depends on utilization of appropriate methods for their isolation. Although anaerobes are generally isolated from only 10% of patients with acute sinusitis, they can be isolated from up to 67% of patients with chronic infection (11). The predominant species include anaerobic gramnegative bacilli (e.g., Bacteroides, Prevotella, and Porpyromonas spp.) anaerobic gram-positive cocci (Peptostreptococcus spp.), and Fusobacterium spp. (4). Many of these aerobic and anaerobic isolates can produce the enzyme b-lactamase (12), which makes the choice of antimicrobial therapy more difﬁcult. The choice of antibiotics should be made based, whenever possible, on the results of appropriate cultures that led to the recovery of isolates. Susceptibility testing of these organisms should guide the clinician in the choice of antibiotics. Sample collection sites include the middle meatus and the sphenoethmoidal recess. The maxillary antral tap and lavage are the recognized gold standards for obtaining cultures. However, this is an invasive procedure. Recent studies have shown that endoscopically directed culture swabs and suction aspirators can lead to comparable results (13,14). However, it is not always possible to obtain a culture using this method, as patients may not present with visible purulence. In these cases, an empirical therapy is chosen. Empirical antibiotics used for CRS should cover the most common aerobic and anaerobic bacterial organisms found in this condition. Treatment against both aerobic and anaerobic bacteria was shown to be superior to treatment against aerobes alone (14). Examples of proper empiric antibiotics include the combination of a penicillin- and a b-lactamase inhibitor (e.g., clavulanic acid), clindamycin, the combination of metronidazole and a macrolide, or a quinolone also effective against anaerobic bacteria (e.g., moxiﬂoxacin) (see Chap. 9 by Brook) (15). ANTIMICROBIAL AGENTS The common b-lactams currently available are the penicillins and the cephalosporins. They are time-dependent, and obtaining a concentration above the MIC into the site of infection for greater than 40% to 50% of the time ensures the highest degree of bacterial death (16). These antibiotics are commonly used in the treatment of acute sinusitis, where they have excellent activity against penicillin-susceptible S. pneumoniae. In CRS, however, there

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is a high incidence of multiple drug-resistant S. pneumoniae and b-lactamase– producing aerobes and anaerobes. For this reason, amoxicillin in combination with a b-lactamase inhibitor (clavulanate) enhances the activity of amoxicillin against these organisms. Second-generation cephalosporins have moderate efﬁcacy against intermediate-level penicillin-resistant pneumococci as well as H. inﬂuenzae. Their use in CRS is limited given their relative lack of activity against aerobic and anaerobic gram-negative organisms. Among the ﬂuoroquinolones, ciproﬂoxacin is used in CRS to treat aerobic gram-negative organisms including Pseudomonas spp. Newer agents, such as gatiﬂoxacin, moxiﬂoxacin, and gemiﬂoxacin, have activity against grampositive and -negative aerobic bacteria as well as some oral anaerobes. The activity of these antibiotics is concentration-dependent, and they are also used in for topical preparations. An effective combination in patients with CRS and osteitic sinonasal bone, effective against the polymicrobial ﬂora, is clindamycin plus trimethoprim–sulfamethoxazole or a third-generation cephalosporin (i.e., ceﬁxime). Clindamycin has good bone penetration, and is effective against resistant strains of S. pneumoniae and b-lactam–resistant anaerobes; trimethoprim– sulfamethoxazole ceﬁxime are active against aerobic gram-negative organisms. Macrolides (i.e., erythromycin, clarithromycin, and azithromycin) and ketolides (e.g., telithromycin) have limited antibacterial use in CRS. There is increasing resistance to the macrolides by S. pneumoniae and S. aureus, and both classes have little activity against gram-negative enteric aerobes and anaerobes. Despite their limited antimicrobial activity, the macrolides may have a role in the treatment of the inﬂammatory aspects in CRS. In vitro studies have shown that macrolides decrease the levels of inﬂammatory cytokines IL-5, IL-8, and G-CSF and have compared their in vitro effects with that of prednisolone (17). Clinical studies of long-term, low-dose macrolide therapy following endoscopic sinus surgery, which is typically onehalf of the doses used for antibacterial effect, have shown subjective and objective improvement as compared to controls (18). More clinical studies are needed, but long-term macrolide therapy may be a well-tolerated anti-inﬂammatory therapy that can be used to limit the use of steroids in the treatment of CRS. One concern regarding the use of long-term macrolide therapy is the possible selection of antimicrobial resistance to this, as well as other classes of antibiotics. ANTI-INFLAMMATORY AGENTS Long-term, low-dose macrolide therapy represents one attempt at controlling the inﬂammation associated with CRS. Agents that possess antiinﬂammatory properties that are well-tolerated are sought to help ease the reliance on systemic corticosteroids.

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Corticosteroids are powerful anti-inﬂammatory agents that affect both the number and function of inﬂammatory cells. When given systemically, they reduce circulation of basophil, eosinophil, and monocyte counts to 20% of normal (19). They have multiple effects on the inﬂammatory response in CRS. They inhibit the secretion of growth factors and mediators of inﬂammatory cell proliferation, the release of arachidonic acid metabolites, the accumulation of neutrophils in the affected tissues, decrease vascular permeability, and thin mucus by inhibiting glycoprotein secretion from submucosal glands (20). When used in a topical form, nasal steroid sprays have been shown to be safe and effective in alleviating the symptoms of allergic rhinitis (21). Their use in patients with CRS is important in decreasing the size of nasal polyps and diminishing sinomucosal edema (22). There are no set guidelines for the duration of their use, and side effects from long-term use are unknown. Anecdotally, patients with allergic rhinitis and nasal polyps use steroid sprays for many years with little side effects. Studies involving the use of oral steroids in the treatment of CRS were not done frequently. These agents represent some of our most effective medications, as they have been shown to decrease the size of nasal polyps, diminish mucosal edema, and promote drainage of obstructed sinus ostia (23,24). Some patients with signiﬁcant and recurrent polyps are maintained on a daily dose of systemic steroids. This can be deleterious to the patients’ overall health because of signiﬁcant side effects. Prolonged oral steroid use may result in muscle wasting and osteoporosis. Bone density scans should be considered in patients on long-term therapy. Extended use may also result in hypertension, redistribution of body fat stores, and may even induce long-lasting suppression of ACTH production, which can result in anterior pituitary and adrenal cortical atrophy. Because of these harmful side effects, steroids are tapered and given in short courses that may span three to four weeks. Short-term side effects include water retention, mood shifts, and an increase in energy, which may result in sleep deprivation. When treating a bout of CRS, patients are often given a tapering dose of prednisone over a threeweek period. It is imperative that the treating physician warn the patient of the potential short- and long-term side effects, and some have even resorted to having patients sign an informed consent form prior to the medical therapy. ADJUNCTIVE THERAPY As stated previously, the medical management of CRS rarely depends on a single medication. In many cases, multiple agents with different mechanisms of action are given in hopes of ultimately promoting drainage of secretions and improved oxygenation to obstructed sinus ostia. One such medication is a decongestant. Decongestants are a-adrenergic agonists that act to constrict capacitance vessels and decrease mucosal

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edema. Topical therapy such as oxymetazoline or neosynephrine may be used in an acute setting, but overuse will result in a rebound effect and rhinitis medicamentosa. Systemic decongestants can be used for longer periods of time, but may cause side effects of insomnia and may exacerbate underlying systemic hypertension (25). Antihistamines are used in common therapy for patients with underlying allergic rhinitis, but their use in patients without atopy may cause more harm than good. They effectively relieve symptoms of itching, rhinorrhea, and sneezing in allergic patients, but in nonallergic patients may result in thickening of secretions, which may prevent the needed drainage of the sinus ostia. A well-tolerated medication that thins secretions to facilitate drainage is a high-dose guaifenesin (glyceryl guaicolate). Given a daily dose of 2400 mg, patients may experience less nasal congestion and thinner postnasal drainage (26). Nasal saline irrigations are also helpful in thinning secretions and may provide a mild beneﬁt in nasal congestion. Although poorly studied, hypertonic saline irrigations have been found to improve patient comfort and quality of life, decrease medication use, and diminish the need for surgical therapy (27,28). This can be done with a 60 cc syringe that is cleaned once a week with rubbing alcohol and replaced every month to help limit the chances of contamination and reinfection. There are a number of commercially available delivery methods, including the water pik device and the netty pot. Nasal irrigations can be used for the duration of symptoms and also as a daily prophylactic measure in those who suffer from recurrent sinus infections and allergic symptoms. Leukotriene inhibitors are systemic medications that block the receptor and/or production of leukotrienes, potent lipid mediators that increase eosinophil recruitment, goblet cell production, mucosal edema, and airway remodeling. Their use in asthma has been well-documented (29), and the class of medications has been recently approved for the use in allergic rhinitis. Their role in CRS and nasal polyposis is much less clear. One case series documents improved subjective and objective results in patients with nasal polyposis on anti-leukotrienes (30), but these studies must be better controlled before a judgment can be made on their utility in the management of CRS and nasal polyposis. MAXIMAL MEDICAL THERAPY FOR CRS The deﬁnition of maximal medical therapy is not universal. The various medications used, timing, and doses may vary between practitioners and across the various specialties that treat this illness. The aim of maximal medical therapy is, however, uniform to promote drainage of obstructed sinus ostia and stagnant secretions, decrease mucosal edema, and eliminate inciting bacteria and/or fungus.

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Table 1 Maximal Medical Therapy for Chronic Sinusitis Broad-spectrum antibiotic—preferably based on a culture of the middle meatus Oral prednisone—starting at 60 mg/day and tapered down over three weeks Nasal hypertonic saline irrigations Nasal steroid spray Oral or nasal antihistamine spray if patient has preceding allergic rhinitis Mucolytic, i.e., guaifenesin

When treating CRS, a CT scan and nasal endoscopy are extremely useful in the initial patient encounter. Pretreatment objective ﬁndings of mucosal edema radiographically and/or purulent secretions, and mucosal edema can be used as a baseline to gauge improvement. Quality of life questionnaires, such as the RSOM-31 form or SNOT-20, are also helpful in documenting subjective improvement through the course of therapy. Once the diagnosis of CRS is made, the treatment regimen consists of a prolonged course of a broad-spectrum antibiotic, oral steroid, nasal saline irrigations, and nasal steroids sprays plus/minus nasal antihistamine sprays based on evidence of atopy (Table 1). The choice of antibiotic is best made with the aid of an endoscopically guided culture of the middle meatus. If one is not attainable, a broad-spectrum antibiotic that covers aerobic gram-positive and -negative bacteria and anaerobes should be chosen. The exact duration of therapy varies, but most preferred to treat with an initial three-week course, with an additional three weeks of therapy for sub-optimal patient response. The course of antibiotics can be accompanied by a three-week tapering course of oral steroids. A healthy patient is started with 60 mg of prednisone a day for four days, followed by 50 mg a day for four days, 40 mg a day for four days, 30 mg a day for three days, 20 mg a day for three days, and then ﬁnally 10 mg a day for three days. During this time period, the patients continues to ﬂush out their nose twice a day with hypertonic saline irrigations and nasal steroid sprays. Other adjunctive methods as outlined above may be tailored to each individual. After the initial three-week therapy, a repeat CT scan and nasal endoscopy is performed. If there is improvement but still signiﬁcant ﬁndings of sinusitis radiographically or endoscopically, an additional three weeks of antibiotics may be prescribed. After this, if the patient still has subjective symptoms and objective ﬁndings of sinusitis, the option of endoscopic sinus surgery is considered. INFECTIONS FOLLOWING FUNCTIONAL ENDOSCOPIC SINUS SURGERY Episodes of rhinosinusitis following functional endoscopic sinus surgery have a slightly different microbiology proﬁle, but are open to more options

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Table 2 Alternatives to Oral Antibiotics in the Treatment of Sinusitis in Previously Operated Patients Topical antibiotic irrigations Nebulized antibiotics Intravenous antibiotics

for medical treatments. Endoscopic cultures are more easily obtained in open sinus cavities. This is important in the medical management of these patients, since there is a higher incidence of recovery of aerobic gram-negative organisms and S. aureus from patients who have had previous surgery compared to non-operated patients (31). Because of the high prevalence of these potentially antimicrobial-resistant organisms, empirical treatment of bacterial infections in these patients is not advised. Endoscopic-directed cultures should be obtained, and antibiotic coverage should be tailored to the corresponding sensitivities. Rigid nasal endoscopy can be used to direct a cultured swab or leukens trap to collect mucus directly from the involved maxillary or ethmoid sinus cavities. Studies have shown equal sensitivity between the different methods of culture collection and near- equivalence to the maxillary antral tap (13,14). Open sinus cavities are not only easier to culture, but they are also more accessible to topical medications. New alternatives in delivery methods of antibiotics and anti-inﬂammatory medications have been employed to directly administer powerful medications to diseased mucosa, and at the same time limit the systemic distribution and potential side effects (Table 2). These methods were ineffective in delivering medicine to the non-operated sinuses (32), but hold promise in those patients who have cavities that are widely exposed and easily accessible.

NEBULIZED MEDICATIONS Nebulized medications have long been known to be an effective delivery mechanism in management of lower respiratory tract infections (33,34). Recently, this delivery method is being used to treat acute exacerbations of CRS in previously operated patients. Intravenous antibiotics are compounded to a nebulized form and delivered to the sinus mucosa through an aerosilezed machine. The choice of the nebulized antibiotic should be based on the results of a culture. Studies have shown an increase in diseasefree intervals and greater 75% response over a 12-week follow-up period (35). Other medications, such as betamethasone, have been tried in an attempt to deliver a strong course of steroids topically and spare the patient from the harmful systemic side effects.

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TOPICAL ANTIBIOTIC IRRIGATIONS Topical preparations share a similar principle as the nebulized medications in that they represent an attempt to deliver intravenous preparations of antibiotics in a topical form directly to the diseased mucosa. Although these preparations are in widespread use, their use has not yet been well documented in the medical literature. Many of the commonly used preparations are directed at aerobic gram-negative organisms commonly seen in patients who have undergone previous surgery. Ceftazadime (36), gentamicin, and tobramycin are examples. Tobramycin preparations have speciﬁcally been used in cystic ﬁbrosis patients awaiting lung transplantation. The sinus and respiratory mucosa of these patients are frequently colonized with Pseudomonas. Transplant programs have used antibiotic irrigations as a preventive measure against colonization with Pseudomonas in patients awaiting a lung transplant (37). Studies examining the use of tobramycin irrigations in children with cystic ﬁbrosis have shown a signiﬁcant decrease in revision sinus procedures and polyp reformation (38). Topical irrigations aimed at the treatment of S. aureus sinus infections have their foundation in the vascular access literature. Methicillin-resistant S. aureus has been increasingly recovered from infected sinuses following sinus surgery. Mupirocin and betadine nasal irrigations are often being utilized in an attempt to treat these patients without using intravenous antibiotics. In addition to topical antibiotics, there are also other medications that have been used in a topical preparation in the treatment of CRS and nasal polyps. One case series demonstrated a decrease in the incidence of post-surgical recurrences of nasal polyps following the topical use of a diuretic (furosemide) (39). Antifungals are also used in a nasal irrigation. Amphotericin B has been shown in two prospective, non-controlled trials to decrease nasal polyps. These studies have a limited follow-up, but have shown the irrigations to be well tolerated and have demonstrated good subjective and objective results (40,41). Even though many of these studies were not randomized or compared to a control group, they show potential for the management of the difﬁcult-to-treat patients, where the other options are much more invasive (i.e., intravenous antibiotics and/or revision surgery).

INTRAVENOUS ANTIBIOTICS The use of intravenous antibiotics in the treatment of CRS has been traditionally reserved for orbital and/or intracranial complications of the disease process. Their use has been well-documented in the management of pediatric sinusitis as an alternative to sinus surgery, as well as the treatment of pediatric orbital complications from ethmoid sinusitis (42,43). Antibiotics that cross the blood–brain barrier are used in conjunction with surgical therapy

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in the management of epidural collections stemming from frontal sinusitis, and in the management of a Pott’s puffy tumor or osteomyelitis of the frontal bone following an acute frontal sinus infection. At least a three-week course of a culture-based parenteral antibiotic is given. When indicated, this is followed, by an additional course of oral therapy to complete a total six weeks, of therapy. If a culture is unavailable, broad-spectrum antibiotics such as a combination of clindamycin or metronidazole with a fourth generation cephalosporin (cefepime or ceftazidime) or single therapy with a carbapenem (i.e., imipenem, meropenem) provide coverage for both anaerobes and aerobes. There are some who are advocating the use of intravenous antibiotics in patients with CRS for patients who have either had unsuccessful surgery, or who have refused surgery, and base their rationale on comparing the disease process of this condition to that of osteomyelitis (44). There is both clinical and experimental evidence to suggest that the bone underlying the diseased sinus mucosa is involved in CRS. In experimentally induced sinusitis with P. aeruginosa using an animal model, Bolger et al. (45) demonstrated bone changes as early as four days after infection of a maxillary sinus. These changes included a coordinated osteoclasis and appositional bone formation adjacent to the sinus, as well as subsequent intramembranous bone formation. Clinical experience with computed tomography and nasal endoscopy has shown bone to undergo resorption followed by subsequent hyperostosis. In addition, studies have shown that ethmoid bone underwent rapid remodeling in CRS that was histologically identical to the remodeling seen in osteomyelitis (46). Follow-up studies have demonstrated that rabbits inoculated with bacterial organisms develop CRS and have histological evidence of chronic osteomyelitis (47,48). It appears that inﬂammation spreads through widened Haversian canal system within the bone and can spread to involve the opposite side. This may help to explain the recalcitrance of severe CRS to medical and surgical therapy, and the clinical observation for tendency of disease persistence in localized areas until the underlying bone is removed. The translation of this research to clinical use where intravenous antimicrobial therapy was given to patients with CRS has not been as persuasive. The studies published so far have largely been uncontrolled, non-randomized case series of a limited number of patients. The majority of indications are for recalcitrant infections resistant to oral antibiotics. The efﬁcacy of the treatment varies among the studies (29–89%), but they are uniform in their relative high rate of complications (14–26%) (49,50) and have resulted in a relapse rate of 89% at a mean follow-up of 11.5 weeks in one study (51). They range from the benign, such as diarrhea, to the serious and life-threatening, such as septic thrombophlebitis and neutropenia (52). Until more studies are performed, intravenous antibiotic use should be reserved for those select cases in which orbital and/or intracranial

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complications arise, or in a chronic infection in which there are no other oral antibiotic alternatives. ASPIRIN DESENSITIZATION The classic Samter’s triad consists of nasal polyps, asthma, and sensitivity to aspirin or NSAIDS that exacerbates the above conditions. Recognition of this disease is not always easily made, since there can be a lag time between presentation of the components of the triad. Studies of these patients have shown that an increase in serum leukotrienes with response to aspirin (ASA) provocation that has a direct result in eosinophil recruitment with subsequent polyp formation and airway remodeling. Clinically, these patients are difﬁcult-to-treat, and do relatively poorly following surgery as compared to non-ASA sensitive patients. ASA desensitization is the slow introduction of aspirin in a controlled, monitored setting. In vitro studies have shown a subsequent decrease in serum leukotrienes to normal levels one year following aspirin desensitization (53). Clinical studies have shown signiﬁcant reductions in prednisone requirements, polyp reformation, and improvement in pulmonary function in follow-up as long as six years (54). Patients are often asked to take 650 mg twice a day for improved nasal breathing, but only 81 mg is required to maintain a desensitized state. CONCLUSION The recognition of CRS as a disease of both inﬂammation and infection is the ﬁrst key step in its medical management. There are multiple choices of antibiotics and anti-inﬂammatory agents, and a combination of both is needed for an extended period of time. Infections following sinus surgery are even more difﬁcult to treat, and antibiotic coverage should be based on an endoscopically guided culture. There are currently more alternatives to conventional therapy in these patients in which medications can be applied topically to the diseased mucosa. REFERENCES 1. Benninger MS, Holzer SE, Lau J. Diagnosis and treatment of uncomplicated acute bacterial rhinosinusitis: summary of the Agency for Health Care Policy and Research evidence-based report. Otolaryngol Head Neck Surg 2000; 122:1–7. 2. Senior B, Glaze C, Benninger MS. Use of the rhinosinusitis disability index in rhinologic disease. Am J Rhinol 2001; 15:15–20. 3. Benninger MS, Ferguson BJ, Hadley JA, et al. Adult chronic rhinosinusitis: deﬁnitions, diagnosis, epidemiology, and pathophysiology. Otolaryngol Head Neck Surg 2003; 129:S1–S32.

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4. Taghizadeh F, Hadley JA, Osguthorpe JD. Pharmacological treatments for rhinosinusitis. Expert Opin 2002; 3:305–313. 5. Ponikau JU, Sherris DA, Kern EB, et al. The diagnosis and incidence of allergic fungal sinusitis. Mayo Clin Proc 1999; 74:877–884. 6. Bernstein JM, Ballow M, Schlievert PM, et al. A superantigen hypothesis for the pathogenesis of chronic hyperplastic sinusitis with massive nasal polyposis. Am J Rhinol 2003; 17:321–326. 7. Bolger WE, Leonard D, Dick EJ, et al. Gram negative sinusitis: a bacteriologic and histologic study in rabbits. Am J Rhinol 1997; 11:15–25. 8. Kaliner MA, Osguthorpe JD, Fireman P, et al. Sinusitis: bench to bedside. Current ﬁndings, future directions. Otolaryngol Head Neck Surg 1997; 116:S1–S20. 9. Gwaltney JM. Acute community-acquired sinusitis. Clin Infect Dis 1996; 23: 1209–1225. 10. Brook I. Microbiology and management of sinusitis. J Otolaryngol 1996; 25:249–256. 11. Finegold SM, Flynn MJ, Rose FV, et al. Bacteriologic ﬁndings associated with chronic maxillary sinusitis in adults. Clin Infect Dis 2002; 35:428–433. 12. Brook I, Yocum P, Frazier EH. Bacteriology and b-lactamase activity in acute and chronic maxillary sinusitis. Arch Otolaryngol Head Neck Surg 1996; 122:418–422. 13. Nadel DM, Lanza DC, Kennedy DW. Endoscopically guided cultures in chronic sinusitis. Am J Rhinol 1998; 12:233–241. 14. Brook I, Frazier EH, Foote PA. Microbiology of chronic maxillary sinusitis: comparison between specimens obtained by sinus endoscopy and by surgical drainage. J Med Microbiol 1997; 46:430–432. 15. Brook I, Thompson DH, Frazier EH. Microbiology and management of chronic maxillary sinusitis. Arch Otolaryngol Head Neck Surg 1994; 120:1317–1320. 16. Brook I. Microbiology and antimicrobial management of sinusitis. Otolaryngol Clin North Am 2004; 37:253–266. 17. Brook I, Yocum P. Antimicrobial management of chronic sinusitis in children. J Laryngol Otol 1995; 109:1159–1162. 18. Wallwork B, Coman W, Feron F, et al. Clarithromycin and prednisolone inhibit cytokine production in chronic rhinosinusitis. Laryngoscope 2002; 112:1827–1830. 19. Moriyama H, Yanagi K, Ohtori N, et al. Evaluation of endoscopic sinus surgery for chronic sinusitis: post-operative erythromycin therapy. Rhinology 1995; 33:166–170. 20. Clerico DM. Medical treatment of chronic sinus disease. In: Diseases of the Sinuses. London: BC Dekker, 2001. 21. Schleimer RP. Glucocorticoids: their mechanism of action and use in allergic diseases. Allergy: Principles and Practice. Mosby 2003; 912–914. 22. Nuutinen J, Ruoppi P, Suonpaa J. One dose beclomethasone dipropionate aerosol in the treatment of seasonal allergic rhinitis. A preliminary report. Rhinology 1987; 25:121–127. 23. Chalton R, Mackay I, Wilson R, Cole P. Double blind placebo controlled trial of betamethasone nasal drops for nasal polyposis. Br Med J Clin Res Educ 1985; 291:788.

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24. Mygand N. Effects of corticosteroid therapy in non-allergic rhinosinusitis. Acta Otolaryngol 1996; 116:164–166. 25. Damm M, Jungehulsing M, Eckel HE, et al. Effects of systemic steroid treatment in chronic polypoid rhinosinusitis evaluated with magnetic resonance imaging. Otolaryngol Head Neck Surg 1999; 120:517–523. 26. Radack K, Deck CC. Are oral decongestants safe in hypertension? An evaluation of the evidence and a framework for assessing clinical trials. Ann Allergy 1986; 56:396–401. 27. Wawrose SF, Tami TA, Amoils CP. The role of guaifenesin in the treatment of sinonasal disease in patients infected with the human immunodeﬁciency virus (HIV). Laryngoscope 1992; 102:1225–1228. 28. Brown SL, Graham SG. Nasal irrigations: good or bad? Curr Opin Otolaryngol Head Neck Surg 2004; 12:9–13. 29. Rabago D, Zgierska A, Mundt M, et al. Efﬁcacy of daily hypertonic saline nasal irrigation among patients with sinusitis: a randomized controlled trial. J Fam Pract 2002; 51:1049–1055. 30. Riccioni G, Santilli F, D’Orazio F. The role of anti-leukotrienes in the treatment of asthma. Int J Immunopathol Pharmacol 2002; 15:171–182. 31. Parnes SM, Chuma AV. Acute effects on anti-leukotrienes on sinonasal polyposis and sinusitis. Ear Nose Throat J 2000; 79:18–20. 32. Nadel DM, Lanza DC, Kennedy DW. Endoscopically guided cultures in chronic sinusitis. Am J Rhinol 1998; 12:233–241. 33. Kobayashi T, Baba S. Topical use of antibiotics for chronic sinusitis. Rhinol Suppl 1992; 14:477–481. 34. Klepser ME. Role of nebulized antibiotics for the treatment of respiratory infections. Curr Opin Infect Dis 2004; 17:109–112. 35. Cole PJ. The role of nebulized antibiotics in treating serious resp infections. J Chemother 2001; 13:354–362. 36. Vaughan WC, Carvalho GC. Use of nebulized antibiotics for acute infections in chronic sinusitis. Otolaryngol Head Neck Surg 2002; 127:558–568. 37. Leonard DW, Bolger WE. Topical antibiotic therapy for recalcitrant sinusitis. Laryngoscope 1999; 109:668–670. 38. Davidson TM, Murphy C, Mitchell M, et al. Management of chronic sinusitis in cystic ﬁbrosis. Laryngoscope 1995; 105:354–358. 39. Moss RB, King VV. Management of sinusitis in cystic ﬁbrosis by endoscopic surgery and serial antimicrobial lavage. Reduction in recurrence requiring surgery. Arch Otolaryngol Head Neck Surg 1995; 121:566–572. 40. Passali D, Mezzedimi C, Passali GC, et al. Efﬁcacy of inhalation form of furosemide to prevent postsurgical relapses of rhinosinusal polyposis. J Otorhinolaryngol Rel Spec 2000; 62:307–310. 41. Ricchetti A, Landis BN, Mafﬁoli A, et al. Effect of anti-fungal nasal lavage with amphotericin B on nasal polyposis. J Laryngol Otol 2002; 116(4):261–263. 42. Ponikau JU, Sherris DA, Kita H, Kern EB. Intranasal antifungal treatment in 51 patients with chronic rhinosinusitis. J Allergy Clin Immunol 2002; 110(6):862–866. 43. Buchaman CA, Yellon RF, Bluestone CD. Alternative to endoscopic sinus surgery in the management of pediatric chronic rhinosinusitis refractory to oral antimicrobial therapy. Otolaryngol Head Neck Surg 1999; 120:219–224.

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44. Sobol SE, Marchand J, Tewﬁk TL. Orbital complications of sinusitis in children. J Otolaryngol 2002; 31:131–136. 45. Anand V, Levine H, Friedman M, et al. Intravenous antibiotics for refractory rhinosinusitis in nonsurgical patients: preliminary ﬁndings of a prospective study. Am J Rhinol 2003; 17:363–368. 46. Bolger WE, Leonard D, Dick EJ, et al. Gram negative sinusitis: a bacteriologic and histologic study in rabbits. Am J Rhinol 1997; 11:15–25. 47. Hwang P, Montone KT, Gannon FH, et al. Applications of in situ hybridization techniques in the diagnosis of chronic sinusitis. Am J Rhinol 1999; 13: 335–338. 48. Khalid AN, Hunt J, Perloff JR, Kennedy DW. The role of bone in chronic rhinosinusitis. Laryngoscope 2002; 112(11):1951–1957. 49. Perloff JR, Gannon FH, Bolger WE, et al. Bone involvement in sinusitis: an apparent pathway for the spread of disease. Laryngoscope 2000; 110:2095–2099. 50. Don DM, Yellon FR, Casselbrant ML, et al. Efﬁcacy of a stepwise protocol that includes intravenous antibiotic therapy for the management of chronic sinusitis in children and adolescents. Arch Otolaryngol Head Neck Surg 2001; 127:1093–1098. 51. Gross ND, McInnes RJ, Hwang PH. Outpatient intravenous antibiotics for chronic rhinosinusitis. Laryngoscope 2002; 112:1758–1761. 52. Fowler KC, Duncavage JA, Murray JJ, et al. Chronic sinusitis and intravenous antibiotic therapy: resolution, recurrent and adverse events. J Allergy Clin Immunol 2003; 111:s85. 53. Tanner SB, Fowler KC. Intravenous antibiotics for chronic rhinosinusitis: are they effective? Curr Opin Otolaryngol Head Neck Surg 2004; 12:3–8. 54. Gosepath J, Schaefer D, Amedee RG, et al. Individual monitoring of aspirin desensitization. Arch Otolaryngol Head Neck Surg 2001; 127:316–321. 55. Stevenson DD, Hankammer MA, Mathison DA, et al. Aspirin densensitization treatment of aspirin sensitive patients with rhinosinusitis-asthma: long-term outcomes. J Allergy Clin Immunol 1996; 98:751–758.

12 Surgical Management David Lewis Department of Otolaryngology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A.

Nicolas Y. Busaba Department of Otolaryngology, Harvard Medical School, VA Boston Healthcare System, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, U.S.A.

INTRODUCTION The surgical treatment of sinus disease has changed dramatically over the past 20 years in the United States and nearly 30 years in Europe. In the past, otolaryngologists relied on using the nasal speculum and a headlight to diagnose and treat diseases of the nasal cavity and paranasal sinuses. Such an examination only allowed for viewing of the anterior components of the nose, and the observer was unable to adequately view the paranasal sinuses or their ostia. For improved visualization and more thorough treatment, open approaches were the only option. There has also been a conceptual shift away from attempting to surgically exenterate the disease within the paranasal sinuses to simply opening speciﬁc areas in order to improve sinus function and allow better aeration and drainage. The amount of tissue removed during sinus surgery is minimized now, and the surgeon relies on opening key functional areas to restore the normal physiology within the paranasal sinuses, which thereby helps to reverse the disease. Since the introduction of nasal endoscopes, the diagnosis and the treatment of sinus disease have changed remarkably. One now has the ability to view the anatomy of the nasal cavity, and at times, the paranasal 233

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Figure 1 Light source and three 4-mm diameter rigid endoscopes. The endoscopes have a zero, 30-degree, and 70-degree viewing angles.

sinuses themselves, up close and with remarkable detail (Fig. 1). Nasal endoscopes use ﬁberoptic light cables to transmit light into the nose. Special optical lenses are used for improved viewing. There are both ﬂexible and rigid endoscopes; the latter are available in many different angled optics systems. These scopes allow for excellent visualization of the entire nasal cavity, both in the ofﬁce and in the operating room, and all of the key paranasal sinus ostia that are involved in sinus disease. The cameras attach to the eyepiece of the endoscope, allow for easy viewing on a television monitor, and also offer the added advantage of using endoscopes for video recording to demonstrate anatomy and pathology to patients in the ofﬁce, and for teaching purposes. DIAGNOSTIC WORK-UP Medical History When a patient with sinus complaints is referred to the otolaryngologist, the evaluation always begins with a thorough history followed by a careful examination of the nose. (Please refer to the chapter on Clinical Presentation and Diagnosis for a more detailed review on the evaluation of a patient with sinus disease). The patient should be asked about symptoms of facial pain or pressure over individual sinuses, headache, nasal blockage, rhinorrhea, postnasal drip, and hyposmia (Table 1). It is very important to ask

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Table 1 Medical History Symptoms Facial pain or pressure Headache Nasal blockage Rhinorrhea Post-nasal drip Hyposmia and/or hypogeusia Previous treatment attempts Antibiotics Steroids Antihistamines Allergen avoidance Previous sinus surgery Past medical and surgical history Other medications Drug allergies Environmental allergies Social history including tobacco smoke exposure Family history Review of systems

about previous attempts at medical management. What antibiotics have been used to treat the symptoms and for how long were they used? Did they improve the symptoms? Is the patient a smoker or exposed to passive smoke or other irritants? Does the patient have an allergic component to the disease process? If so, have these issues been maximally treated medically with antihistamines, nasal steroids, or other medications? Is the patient a candidate for immunotherapy? Is allergen avoidance a realistic possibility for the patient? What other comorbidities does the patient have? These questions are important to ensure that all patients have been given the most optimal attempt at medical management prior to making any decisions about surgery. Physical Examination As part of the head and neck evaluation, a thorough nasal examination should be completed in the ofﬁce. Anterior rhinoscopy using a headlight or mirror and a nasal speculum should be performed prior to any attempts at nasal decongestion. Any evidence of mucopurulent discharge, nasal polyps, enlarged turbinates, nasal septal deviation, or diseased mucosa should be noted. Using either a rigid or ﬂexible endoscope, one can almost always view the middle meatus and the sphenoethmoid recess. Decongestion and anesthesia with a sprayed mixture of 4% lidocaine with phenylephrine

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Figure 2 Endoscopic view of an inﬂammatory polyp in the left middle meatus.

facilitates this part of the examination. The ﬁndings noted on anterior rhinoscopy can be conﬁrmed. Additionally, one might see limited areas of inﬂammation, mucopurulent discharge, and/or polypoid changes that could not be seen during the initial rhinoscopic examination (1) (Fig. 2). Imaging Based on the history and examination ﬁndings, a decision is made whether or not to obtain a computed tomography (CT) scan. Noncontrast CT scans, particularly in the coronal plane, can be very helpful both for diagnosis and pre-operative planning if surgery is indicated. CT scans can conﬁrm sinusitis, and they can offer the surgeon valuable information about the patient’s anatomy that can be used to help avoid complications during surgery. Occasionally, a CT scan can also be useful in ruling out sinus disease in a patient with convincing sinus complaints but no evidence of disease on exam. Additionally, the CT scan has become a valuable tool in image-guided sinus surgery (see following sections). INDICATIONS FOR PARANASAL SINUS SURGERY There is currently a wide range of indications for paranasal sinus surgery (Table 2). The most common indication is for chronic rhinosinusitis (CRS).

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Table 2 Indications for Paranasal Sinus Surgery 1. Inﬂammatory or infectious rhinosinusitis Chronic rhinosinusitis that failed medical therapy Recurrent rhinosinusitis Symptomatic nasal polyposis Acute or chronic rhinosinusitis with periorbital or intracranial complications Invasive fungal sinusitis Fungus ball-mycetoma 2. Sinonasal neoplasm (benign and malignant) 3. Repair of skull base defects CSF rhinorrhea Menigoceles or meningoencephaloceles 4. Approach for excision of intracranial pathology Pituitary tumors Petrous apex cholesterol granuloma 5. Control of epistaxis 6. Orbital decompression for Graves’ ophthalmopathy 7. Removal of sinus foreign bodies 8. Management of nasolacrimal duct obstruction

Patients who continue to have signs and symptoms of rhinosinusitis despite maximal medical therapy are often candidates for sinus surgery. Maximum medical therapy has not been standardized, but typically involves four to six weeks of broad-spectrum oral antibiotics used in conjunction with decongestants and mucolytic agents. Patients with allergies are often also given antihistamines and intranasal steroid sprays. Surgery may also be considered in patients who have repeated episodes of acute rhinosinusitis that clears with antibiotics. Although there is no agreed treatment algorithm for patients with recurrent rhinosinusitis, many rhinologists feel that if the frequency and severity of the patient’s symptoms are sufﬁcient to interfere signiﬁcantly with school or work, then surgery is a reasonable option (2). Prior to surgery, it is important to rule out non-sinus causes of a patient’s symptoms, i.e., atypical migraines or other neurologic causes including neuralgia. Another indication for sinus surgery is to treat patients with symptomatic nasal polyposis. The pathophysiology of polyp formation is poorly understood. However, polyps are commonly associated with asthma and environmental allergies. On the other hand, it is not unusual to diagnose polyps in a patient without atopy or asthma. An antral-choanal polyp is such an example. Unfortunately, medical therapy is rarely sufﬁcient to control nasal polyposis and surgery is often indicated. Patients should be counseled about the high recurrence following surgery. Special attention must be given to those patients with asthma, particularly those with aspirin-sensitivity (Samter’s triad). These patients often require preoperative corticosteroids and maximal bronchodilator therapy to optimize their

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pulmonary status. The corticosteroids may also serve to shrink the polyps and possibly decrease their risk of recurrence. Aspirin-desensitization may also be beneﬁcial in these patients. It is important to note that the differential diagnosis of nasal polyps includes some benign and malignant tumors. Hence, at the time of surgery, tissue specimens should be sent for permanent pathology in all cases. Unilateral disease, a rubbery or ﬂeshy, highly vascular, or ulcerative appearance, or CT evidence of bone destruction should alert one to the possibility of a neoplasm. In addition to the more common above-mentioned indications, sinus surgery can be performed to treat allergic fungal sinusitis and periorbital and intracranial complications of sinusitis; marsupialize muco(pyo)celes; control epistaxis; remove maxillary sinus foreign bodies; repair anterior skull base cerebrospinal ﬂuid (CSF) leaks or meningo(encephalo)celes; decompress the orbit in patients with Graves’ ophthalmopathy; dacrocystorhinostomy; approach and remove pituitary tumors, petrous apex cholesterol granulomas or other skull base lesions; resect benign neoplasms (osteomas, inverting papillomas, or ﬁbrous dysplasia); and decompress the optic nerve (2).

CONTRAINDICATIONS FOR PARANASAL SINUS SURGERY The only true contraindication to paranasal sinus surgery is the absence of sinus disease. Patients with migraine headaches or other neurological causes of facial pain should not be operated on. Additionally, surgery is not a substitute for medical management; patients with CRS, as mentioned above, should be given maximum medical therapy prior to being offered surgery. A bleeding disorder can place a patient at an increased risk for postoperative hemorrhage, but does not in itself represent a contraindication to surgery.

ENDOSCOPIC (ENDONASAL) SINUS SURGERY The techniques for performing endoscopic sinus surgery were ﬁrst described by Messerklinger during the 1970s. These techniques were later introduced into the United States during the mid-1980s by Kennedy, who coined the term ‘‘Functional Endoscopic Sinus Surgery’’ (FESS) to describe a minimally invasive approach to improve drainage of the paranasal sinuses for the treatment of CRS (3–6). Endoscopic endonasal surgery (EES) or endoscopic sinus surgery (ESS) are other terms commonly used to describe the same operation and can be used interchangeably. FESS involves opening up narrow areas within the nose and paranasal sinuses that are responsible for the pathological changes seen in CRS. Messerklinger studied patterns of mucociliary clearance and noted that in narrow areas of mucosal contact, mucociliary clearance was disrupted (6,7). When this occurs, the mucus becomes either stagnant or recirculated

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Figure 3 CT image (coronal projection) through the ostiomeatal unit (OMU).

within the affected sinus rather than freely draining into the nasal cavity and nasopharynx. Stagnant or recirculated mucus predisposes the patient to infection, which leads to inﬂammation that further impedes mucociliary clearance, resulting in increased infection followed by more inﬂammation, and then a vicious cycle ensues. The two primary areas of narrowing that can impair mucociliary clearance and lead to problems with CRS are the ethmoidal infundibulum and the frontal recess. These two anatomical points of narrowing are both located in the anterior ethmoid area within the middle meatus. Many rhinologists use the term osteomeatal complex (OMC) or osteomeatal unit (OMU) to describe this functional area where narrowing can occur (Fig. 3). The ethmoidal infundibulum is a three-dimensional space that is a convergence point for mucus ﬂowing from the anterior ethmoid air cells, the maxillary sinus, and the frontal sinus (8). Similarly, the frontal recess is a narrow area in which mucus from the frontal sinus must pass prior to reaching the ethmoidal infundibulum (1,6–8). This area can be further narrowed by projections from the most anterior of the ethmoid air cells, the agger nasi cells (Fig. 4). FESS aims at opening up these two key areas of narrowing to allow adequate drainage of the frontal, anterior ethmoid, and maxillary sinuses. When widespread disease affects all paranasal sinuses, ESS can be tailored to treat all the involved areas. There are two primary goals of FESS. The ﬁrst is to open up the narrow areas described above. The second is to perform the surgery in as

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Figure 4 CT image (coronal projection) showing a right agger nasi cell.

atraumatic a manner as possible (1,6–8). Accordingly, sinus surgeons must remove the anatomical areas of obstruction without disturbing the surrounding healthy mucosa. In order to open a narrowed ostiomeatal complex, a thin piece of bone called the uncinate process is carefully removed in its entirety. Additionally, an ethmoid air cell called the ethmoid bulla is typically removed to allow better drainage (Fig. 3). Any further removal of tissue is dependent on the extent of disease. Some believe that an uncinectomy with an ethmoid bullectomy is all that is necessary during FESS and coined the term minimally invasive sinus technique (MIST) (9). The majority of rhinologists recommend a more complete ethmoidectomy in addition to widening of the maxillary ostium and opening of the frontal recess cells. All agree, however, that any diseased mucosa that is not a direct component of the osteomeatal complex should not be removed or manipulated because this surrounding area of disease will eventually revert to normal once there is a wide open area for drainage and aeration (8). In other words, one does not need to strip away all of the diseased mucosa because paranasal sinus

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Figure 5 Schematic representation of endoscopic sinus surgery. (A) Coronal projection through the OMU. The shaded area represents the ethmoid sinus. (B) Schematic drawing of the procedure. (C) Ethmoid sinus cavity at the end of surgery with patent maxillary antrostomy and frontal recess. Note that the uncinate process has been removed. Abbreviations: UP, uncinate process; MT, middle turbinate; S, septum.

mucosal pathology can be reversed by improving the ventilation and drainage of the involved sinus (Fig. 5). By minimizing mucosal disruption, one can minimize postoperative scarring. This is very important because some areas of scar tissue formation can be devoid of the respiratory epithelium required for mucociliary clearance. If there are large areas of scar, then mucus will stagnate. Additionally, mucosal

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Figure 6 Adhesions in a right ethmoid cavity in a patient with previous endoscopic ethmoidectomy.

disruption with scarring often results in ﬁbrous adhesions that can re-obstruct the drainage of mucus resulting in recurrence of sinus disease (Fig. 6). In these instances, a revision surgery may be required. The role of several anatomical ﬁndings that are noted on CT or nasal endoscopy in the pathophysiology of rhinosinusitis is controversial (10). These include Haller cells, agger nasi cells, concha bullosa, and paradoxical middle turbinate. A Haller cell is an ethmoidal cell that is located along the ﬂoor of the orbit and can narrow the maxillary outﬂow tract (Fig. 7). An agger nasi cell is the anterior-most cell of the ethmoid sinus and may represent pneumatization of the lacrimal bone. Agger nasi cells can narrow the frontal recess (Fig. 4). A concha bullosa is a pneumatized middle turbinate. When large, it can conceivably narrow the OMU (Fig. 8). A paradoxical middle turbinate is convex along its lateral wall instead of the medial wall (Fig. 9). Similar to a concha bullosa, a paradoxical middle turbinate can narrow the OMU. All of the above-mentioned anatomical ﬁndings are very prevalent and may be better labeled as anatomical variants, not anomalies. Surgery is not indicated to treat them in the absence of clinical rhinosinusitis. On the other hand, these anatomical ﬁndings need to be addressed during ESS that is indicated to treat CRS. The concept of OMU is valid when the pathophysiology of the CRS is believed to be infectious. More recent theories about the pathogenesis of

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Figure 7 Bilateral Haller cells that narrowed the maxillary outﬂow tract as seen on a CT scan (coronal projection).

Figure 8 Large left concha bullosa. A smaller concha bullosa can be seen on the right side. (CT scan; coronal projection).

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Figure 9 Paradoxical left middle turbinate. Note that the middle turbinate is convex on the lateral surface.

rhinosinusitis stress the role of inﬂammation as the primary event, i.e., rhinosinusitis is primarily an inﬂammatory and not an infectious disease. The inﬂammation is believed to be predominantly caused by the inﬂammatory mediators that are released by eosinophils, usually in response to the presence of fungi or other superantigens in the nose or sinus mucus (eosinophilic CRS) (11,12). In such a case, the role of ESS is to reduce the offending antigen load by allowing repeated cleaning of inspissated mucus from the sinus cavities in the ofﬁce by opening their ostia, which in turn can reduce the inﬂammation. Therefore, ESS in this clinical scenario has a complementary function, and is not a substitute to medical therapy. The patients who undergo ESS typically are given perioperative antibiotics. Coverage is aimed at preventing acute infection by normal ﬂora that has pathogenic potential, such as Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus inﬂuenzae, or alpha streptococci. A common choice for an antibiotic would be a ﬁrst-generation cephalosporin, such as cephalexin. Other choices include clindamycin or azithromycin, the former of which covers anaerobes as well. It should be noted that although there are data to support the use of perioperative antibiotics for other types of surgery, there is no proven beneﬁt to the use of postoperative prophylactic antibiotics after ESS (13,14). When inﬂammatory rhinosinusits is complicated by chronic infection, at least 2 weeks of culture driven antibiotics may be used perioperatively in order to decrease intraoperative bleeding.

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The majority of ESSs can be done on an outpatient basis. The surgery typically takes between 45 minutes and two hours to perform, depending on the extent of surgery. Although this rarely is a painful surgery, patients are sent home with a prescription for analgesics, which at times contain a narcotic. However, many patients only require regular acetaminophen for analgesia. Like in any other surgery, patients are instructed that they must avoid aspirin and nonsteroidal anti-inﬂammatory medications for two weeks prior to and at least one week after surgery. Patients can often return to work after a couple of days; however, they are advised to avoid physical exertion for one to two weeks. Additionally, they are instructed to avoid hot liquids and spicy foods to prevent intranasal vasodilation that might result in epistaxis. Postoperative care is of utmost importance. In order to prevent recurrence of the disease secondary to scarring, patients must return for intranasal debridements on a routine basis for up to six weeks after surgery. If intranasal packing was placed for hemostasis, it can be removed on the ﬁrst postoperative day. Any material that may have been used to stent open the middle meatus is typically removed at the ﬁrst or second ofﬁce visit. If adhesions are found between the middle turbinate and lateral nasal wall or restenosis is noted of the maxillary antrostomy or frontal recess at any point during routine follow up, this can often be successfully treated under local anesthesia in the ofﬁce. Additionally, irrigation is a very effective method that patients can use at home to remove crusts and clots. Many surgeons have their patients started on saline irrigations immediately after surgery and continue irrigating until the healing process is complete. Using a combination of nasal irrigation and in-ofﬁce debridements, one can often prevent complications that might otherwise have resulted in recurrence of disease and the need for revision surgery (8,15). COMPLICATIONS OF ENDOSCOPIC SINUS SURGERY When sinus surgery is performed by experienced surgeons who have a detailed knowledge of sinus anatomy, complications are extremely rare. However, complications can and do occasionally occur, even with the most seasoned of surgeons (Table 3). A small amount of bleeding is expected postoperatively. Nasal packing, and, at times, hemostasis in the operating room can control major bleeding. Postoperative infection is uncommon. When an infection does occur, ofﬁce debridement and an oral antibiotic which is determined by culture of the sinus cavity are usually sufﬁcient treatment. As mentioned above, scarring with adhesions and restenosis of ostia can occur. If the ofﬁce-based treatments fail, then these patients may require a revision surgery. The paranasal sinuses are surrounded by a number of important structures, which can be potentially injured during sinus surgery. Injury to the anterior skull base can result in a CSF leak. If this is identiﬁed during

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Table 3 Complications Bleeding Infection Adhesions Restenosis CSF leak Periorbital hematoma Subcutaneous emphysema Diplopia Blindness Epiphora

surgery, then it can be repaired at the time of the incident. If a CSF leak is noted postoperatively, then the patient is placed on bed rest with the head elevated, either with or without placement of a lumbar drain depending on the severity of the leak. These leaks may close spontaneously. Those that do not close can be repaired via either an endoscopic or an open approach, the latter being performed by a neurosurgeon (8,16). Injury to the medial wall of the orbit can result in a retro-orbital hematoma, diplopia, subcutaneous orbital emphysema, or blindness. If the lamina papyracea and periorbita are entered, then blood can accumulate in the orbit. Usually this only results in periorbital ecchymosis; however, patients must be closely monitored for signs of increased intraocular pressure. An ophthalmologist should be consulted immediately because an elevated intraocular pressure for a prolonged interval causes ischemia to the optic nerve, which can result in blindness. Direct injury to the optic nerve along the superior-lateral wall of the sphenoid sinus or posterior aspect of the lamina papyracea (in the region of annulus of Zinn) can similarly cause blindness. The presence of an Onodi cell (a posterior ethmoid air cell that is lateral and at times posterior to the sphenoid sinus) is associated with an increased incidence of optic nerve injury since the nerve may be dehiscent and pass through the cell. Such an anatomic variant can be detected on a preoperative CT (Fig. 10). Blindness can also rarely result from the dissection of local anesthetic containing decongestants (epinephrine) towards the orbital apex, which can cause spasm of the central retinal artery. Diplopia can occur if inadvertent entry into the orbit results in injury to the medial rectus muscle or violation of the periorbita that results in extensive herniation of intraorbital fat. Subcutaneous orbital emphysema occurs if there is injury to the lamina papyracea and the patient inadvertently performs a Valsalva maneuver during vomiting, sneezing, or nose blowing, which usually resolves spontaneously. Damage to the nasolacrimal duct may occur following sinus surgery, resulting in epiphora and possibly dacrocystitis. The nasolacrimal duct runs

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Figure 10 CT (axial projection) showing a left Onodi cell (a posterior ethmoid cell that extends lateral and at times posterior to the sphenoid sinus).

anterior to the anteromedial wall of the maxillary sinus. Hence, an aggressive anterior maxillary antrostomy can accidentally damage this duct as it travels to the inferior meatus (8,16). Fortunately, these complications are very uncommon. However, patients must be aware of and understand the implications of each of these complications prior to consenting to any form of sinus surgery.

IMAGE GUIDANCE SYSTEMS The advent of image-guided sinus surgery has had a dramatic impact on ESS. Although it is not a substitute for experience and anatomical knowledge, image-guided surgery has allowed rhinologists to perform challenging and complicated endoscopic procedures with increased conﬁdence and precision. Image guidance systems consist of a computer workstation that displays three-dimensional images of the patient’s paranasal sinuses using information obtained from preoperative CT scans. Either an infrared or an electromagnetic signal is used to track the position of a probe or surgical instrument relative to the patient’s head (17). Hence, a surgeon can place the tip of an instrument on, for example, the middle turbinate, and see a

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Figure 11 Image guidance system. Right upper, left upper, and left lower images are sagittal, coronal, and axial projections of CT scan with the cross-hairs indicating the position of the probe during surgery. The probe is inside the right sphenoid sinus. The right lower image shows a simultaneous endoscopic view into the sphenoid sinus.

real-time representation of the probe in coronal, axial, and sagittal planes. This can be done to within 2 mm of accuracy (18–20). They can, therefore, be used to conﬁrm certain anatomical locations that are of interest to the surgeon, for example, the lamina papyracea, the skull base, the frontal recess, the sphenoid sinus, or any other area accessible by the probe (Fig. 11). This is particularly helpful in revision cases where the normal anatomical landmarks are obscured. The major limitations to widespread use of this technology are the increased cost and operative time that it requires (18). MICRODEBRIDERS AND SINUS SURGERY Mechanical debriders are becoming more and more popular in the ﬁeld of ESS. These powered instruments precisely shave tissue using an oscillating burr connected to a suction machine (Fig. 12). When used correctly, these mechanical microdebriders can minimize trauma to the tissues and help to

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Figure 12 A picture of a microdebrider (Diego Microdebrider; Xomed, USA). The insert is a magniﬁed view of the tip of the microdebrider showing its serrated edges (‘‘aggressive cutter’’), which has a 4 mm diameter tip.

preserve normal tissue. In contrast, the use of traditional endoscopic instruments can occasionally tear or strip away healthy mucosa leaving exposed bone, which results in increased crusting and risk of scarring (21,22). The microdebrider can remove diseased tissue quickly and efﬁciently, which is particularly helpful in cases of nasal polyposis when there can be profuse intraoperative bleeding. The main disadvantages to this technology are the cost, the slightly increased set-up time required, and the repeated clogging of the instrument by the resected tissue. Additionally, aggressive use of a microdebrider through an iatrogenic or disease-related dehiscence of the lamina papyracea or fovea ethmoidalis (roof of the ethmoid sinus) can lead to injury of intraorbital or intracranial structures, respectively. TYPES OF PARANASAL SINUS SURGERY The type of surgery performed on a patient depends on the extent and nature of the disease. Now that ESS has become the standard of care for the surgical management of uncomplicated CRS, open approaches to the sinuses are utilized far less often than in the past. Nonetheless, many open procedures are still indicated in select cases. Additionally, there are instances when only a single paranasal sinus needs to be surgically addressed. This section describes the various surgical approaches speciﬁc to each individual paranasal sinus. Maxillary Sinus Surgery Antral Puncture and Lavage This procedure takes approximately 10 minutes and can be performed under local anesthesia via two approaches: the canine fossa or the inferior meatus. In the ﬁrst approach, a small stab incision is made in the upper gingivobuccal sulcus and the anterior bony wall of the maxillary sinus is then entered. In

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Figure 13 Schematic representation of the right maxillary sinus. The white rectangle represents the area in the inferior meatus where antral puncture or inferior nasoantral window is performed.

the latter approach, the thin bone of the medial maxillary wall is punctured in the inferior meatus (Fig. 13). Either approach can be performed under local anesthesia. The maxillary sinus cavity may then be aspirated and the contents sent for microbiology. The cavity can also be irrigated (lavage) with saline or antibiotic-containing solution. This procedure is indicated for symptomatic relief of acute maxillary sinusitis or for obtaining a culture to guide in the choice of an antimicrobial, usually in the ICU setting or with immunocompromised patients. The main disadvantages are the discomfort and the risk of bleeding. Inferior Nasoantral Window The technique is similar to antral puncture through the inferior meatus (Fig. 13). However, in this instance, a wider opening is created in the medial wall of the maxillary sinus to allow for permanent drainage and aeration. The procedure can be performed under local or general anesthesia. This procedure can be particularly helpful in patients with congenital or acquired ciliary dyskinesia since it provides for gravitational drainage of the maxillary sinus secretions. However, there is a high incidence of stenosis or

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complete closure of the window. In addition, maxillary sinus disease may persist despite a patent inferior nasoantral window since the mucociliary clearance drives the mucus towards the natural ostium and that may still be obstructed. Endoscopic Middle Meatal Antrostomy As mentioned earlier in this chapter, ESS has become the mainstay of surgical treatment of both chronic and recurrent maxillary rhinosinusitis. In order to gain endoscopic access to the maxillary sinus, one must surgically remove the uncinate process in order to open up the ethmoidal infundibulum. Once this is done, the natural maxillary sinus ostium can typically be seen. This can be enlarged if necessary through the posterior fontanelle (Fig. 14). Obstructive anatomic abnormalities, such as Haller cells, can also be addressed. This is usually sufﬁcient to treat the maxillary disease without the need for stripping the maxillary sinus mucosa. Establishing adequate aeration and drainage of the maxillary sinus by opening its natural ostium can reverse the disease in the sinus mucosa. This technique is also utilized to remove mycotic ‘‘fungus balls’’ or symptomatic mucus retention cysts, marsupialize muco(pyo)celes of the maxillary sinus, and excise antrochoanal polyps (23,24) (Fig. 15). In the latter cases, a 30-degree or a 70-degree rigid endoscope is used to view the entirety of the maxillary sinus cavity to ensure complete excision, which reduces recurrence. The main advantages in using an endoscopic approach is that it avoids the need for an incision, it is relatively quick, and often can be performed on an outpatient basis. The primary disadvantage is the risk of being unable to fully remove disease in the most lateral recesses of the sinus or along its ﬂoor. This is particularly relevant during excision antrochoanal polyp or maxillary sinus retention cyst where recurrences following endoscopic approach can be up to 50% (24). For this reason, many surgeons will often consent select patients for a Caldwell-Luc procedure (see following section) in case an endoscopic approach does not provide adequate exposure to sufﬁciently treat the disease. Clinical failures of middle meatal antrostomy can be attributed to ciliary dyskinesia or to its occlusion by scar tissue. Optimal postoperative care with ofﬁce endoscopic debridement in the immediate postoperative period can prevent adhesions in the middle meatus and hence occlusion of the antrostomy. Caldwell-Luc Procedure The Caldwell-Luc procedure has been used for over a hundred years to gain access to the maxillary sinus. The Caldwell-Luc procedure involves opening up the anterior wall of the maxillary sinus through the upper gingivobuccal sulcus. A ﬂap of gingiva and periosteum is used to obtain access to the sinus. Unlike the endoscopic approach, the maxillary sinus mucosa is typically stripped and removed during a Caldwell-Luc operation. The procedure

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Figure 14 (Caption on facing page)

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Figure 15 Left antrochoanal polyp. (CT image; coronal projection).

takes approximately one hour. Postoperatively, the patient may or may not have packing in the sinus depending on the amount of bleeding during the case. Some surgeons will apply ice to the upper lip or a pressure dressing to minimize postoperative swelling. Prophylactic antibiotics targeted at normal oral ﬂora are often given perioperatively for ﬁve to seven days. Complications are relatively uncommon and include facial swelling, bleeding, and infection. Transient, or rarely permanent, anesthesia of the upper lip and teeth due to a stretch-on or a transection of the infraorbital nerve can occur. This typically subsides within weeks to months in the earlier case but is permanent in the latter (25). An oroantral ﬁstula can develop from nonhealing of the gingivobuccal sulcus incision. Current indications for the Caldwell-Luc procedure include the removal of mycotic ‘‘fungus balls,’’ symptomatic multiseptate mucoceles of the maxillary sinus, antrochoanal polyps that cannot be removed in their J Figure 14 (Facing page) Endoscopic intraoperative views during right middle meatal antrostomy. (A) View of the middle meatus showing the uncinate process. (B) An incision (arrows) is made at the attachment of the uncinate process. (C) The maxillary ostium (arrow) is visualized following the uncinectomy.

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Table 4 Indications for Caldwell-Luc Removal of mycotic ‘‘fungus balls’’ Symptomatic multiseptate mucoceles of the maxillary sinus Antrochoanal polyps Biopsy and/or removal of neoplasms or other masses Exposure to the pterygopalatine fossa (particularly for epistaxis control) Oroantral ﬁstula repair

entirety via ESS, and neoplasms (Table 4). Additionally, this procedure provides excellent exposure to the pterygopalatine fossa and can be used for closure of oroantral ﬁstula and the biopsy of lesions within the maxillary sinus that are suspicious for malignancy (26). A relative contraindication to the procedure involves those pediatric patients with deciduous teeth because entry into the sinus by this approach may damage the permanent dentition. The advantage of this procedure is the increased exposure and access to the maxillary sinus. The disadvantages are the potential risks listed above that are associated with the procedure and the need for an external incision, which increases postoperative pain. In addition, maxillary sinus mucoceles can form several years following the procedure due to entrapment of the sinus mucosa (27). Ethmoid Sinus Surgery Endoscopic Endonasal Ethmoidectomy As previously mentioned, FESS involves opening the anterior ethmoid air cells in order to improve aeration and drainage with the paranasal sinuses (ostiomeatal unit). Depending on the extent of the disease, the amount of surgery can range from opening up a single ethmoid air cell to opening every cell. The least extensive surgery involves opening the ethmoid bulla and removal of the uncinate process. Agger nasi cells, when present, are removed in patients with frontal sinusitis. Penetrating the basal lamella (insertion of the middle turbinate along the lateral nasal wall) is needed to gain access to the posterior ethmoid cells to treat disease in that area. Healthy mucosa in uninvolved ethmoid cells is preserved. Similarly, the middle turbinate is commonly preserved (Fig. 5). At times, a partial anterior–inferior middle turbinectomy is performed to reduce middle meatal adhesions and facilitate viewing of the middle meatal antrostomy in the ofﬁce. Indications for endoscopic ethmoidectomy have been already mentioned earlier in this chapter. The advantages are that there is no incision required and the patients recover quickly with minimal postoperative pain. The potential complications of the procedure were detailed earlier in the chapter. In addition, ethmoid mucoceles can form several years following

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Figure 16 Endoscopic view of an ethmoid mucocele (arrow) in a patient with previous endoscopic ethmoidectomy.

the surgery, secondary to entrapment of sinus mucosa (Figs. 16 and 17) (28). Avoiding trauma to healthy mucosa and repeated postoperative cleaning and debridement of the ethmoid cavity can reduce the incidence of mucoceles. External Ethmoidectomy An external ethmoidectomy requires that a skin incision be made in order to enter the ethmoid and therefore results in an often barely perceptible scar on the lateral aspect of the nasal dorsum. This procedure takes one to two hours. As with other sinus surgeries, prophylactic perioperative antibiotics are often given. Patients are instructed to place ice over the wound for 24 hours postoperatively and sutures are removed on postoperative day 5. Intranasal postoperative care is similar to the endoscopic procedures, as are the potential complications of the procedure. Additional possible complications include medial canthal scarring and injury to the trochlea or enopthalmos if too much bone is removed (27). The main advantage of this procedure is that it provides excellent visualization and exposure of the medial orbit, ethmoid sinuses, and anterior skull base. Additionally, when the procedure is performed to treat acute ethmoiditis with periorbital abscess, a drain that can be used for irrigation of the ethmoid cavity can be placed. The main disadvantage is that it

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Figure 17 CT image (coronal projection) showing a left posterior ethmoid mucocele that formed ﬁve years following an endoscopic ethmoidectomy.

requires an incision, that can result in a cosmetic deformity. Additionally, the incision carries the risk of a sinocutaneous ﬁstula. External ethmoidectomy continues to have a role in otolaryngology. Although it no longer is used for the treatment of CRS, it is currently indicated for the treatment of acute ethmoiditis complicated by a periorbital or orbital abscess. This approach is also used for the following: for open dacrocystorhinostomy, for complete excision of ethmoid mucocele’s with frontal or orbital extension, for orbital decompression or exanteration, for repair of CSF leak or anterior skull base meningo(encephalo)celes, and additionally, as an adjunctive procedure to assist with craniofacial resections and medial maxillectomies (27). Although there are no absolute contraindications to this procedure, one might argue that it is not an acceptable ﬁrst-line surgical therapy for CRS given the widely available and less morbid endoscopic approaches. Sphenoid Sinus Surgery Endoscopic Endonasal Sphenoidotomy Like the maxillary and ethmoid sinuses, the sphenoid sinus can be similarly opened via an endoscopic approach. The sphenoid sinus can be opened up in conjunction with an endoscopic ethmoidectomy in cases with pansinusitis.

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Figure 18 Endoscopic view of a right sphenoidotomy.

On the other hand, isolated sphenoid sinus disease can be successfully treated by an endoscopic sphenoidotomy without the need for an ethmoidectomy (29). In such a case, the sphenoid ostium is accessed between the nasal septum medially, the roof of the posterior choana inferiorly, and the middle and superior turbinates laterally. The sphenoid ostium is above the level of the sinus ﬂoor and, therefore, the sphenoidotomy is enlarged in an inferior and medial direction. The posterior septum (vomer bone) and the intersinus septum may be drilled for improved drainage and access, if necessary. As is the case with sinus surgery in general, nondiseased mucosa is preserved (Fig. 18). Indications for sphenoidotomy include sphenoid sinusitis with or without polyposis, especially in patients with symptoms of retro-orbital headaches or pressure, the removal of or marsupialization of mucoceles or mucopyeloceles, the removal of mycotic ‘‘fungus balls,’’ or to assist neurosurgeons in their approach to removing pituitary lesions or other skull base lesions (Fig. 19). The management of these patients is the same as for other endoscopic surgeries; however, it should be noted that the internal carotid artery and the optic nerve run along the lateral and superior

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Figure 19 A patient who presented with occipital and vertex headache and was later diagnosed with chronic invasive fungal sinusitis based on the clinical presentation and histopathology. (A) CT scan (axial projection) showing a completely opaciﬁed left sphenoid sinus. (B) Intraoperative endoscopic view of the sinus cavity following sphenoidotomy. The sphenoid sinus was ﬁlled with fungal debris and hyphae.

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walls of the sphenoid sinus, and either can be dehiscent. Hence, surgeons must look carefully for any bony dehiscences on CT scan and be extra cautious when working in this area. Complications of the procedure include bleeding, stenosis/closure of the sphenoidotomy, and injury to the vital structures that are in close proximity to the sinus. External Spenoethmoidectomy The majority of sphenoid sinus lesions can be addressed via an endoscopic approach; however, in select cases, an external sphenoethmoidectomy can be used to approach this sinus. This involves performing an external ethmoidectomy and then opening the anterior wall of the sphenoid to gain access to the sinus. This opening is then connected to the natural ostium. A middle turbinectomy is also performed for improved access. The main indication for this approach is for access to skull base tumors or repair of large defects in the skull base. Similar to an external ethmoidectomy, the main advantage of an external sphenoidotomy is that it can provide increased exposure, working room, and if necessary, can be used in conjunction with a microscope for improved visualization. The disadvantage is that it requires an external incision with its potential complications (see external ethmoidectomy). Frontal Sinus Surgery Trephination Frontal sinus trephination involves making an opening in the inferior wall of the frontal sinus through an incision along the inferior aspect of the medial eyebrow. The inferior wall of the frontal sinus is devoid of bone marrow, which averts the risk of developing osteomyelitis in the setting of frontal sinusitis. The sinus cavity is then irrigated with saline or antibioticcontaining solution. The entire procedure takes less than 30 minutes. A drain may be placed for continued irrigation of the sinus. This procedure is indicated in cases of complicated acute frontal sinusitis. Additionally, it can be used in conjunction with endoscopic approaches to the frontal sinus in chronic frontal sinusitis or frontal sinus mucoceles, when the trephination is used to positively identify the frontal duct and pass a catheter through it into the nasal passage to stent it and prevent its stenosis. The main advantage to this approach is that it provides fast and easy access to the frontal sinus. It also affords the surgeon an opportunity to place a drain in the sinus for irrigation. Its main disadvantages are its associated scarring, risk of sinocutaneous ﬁstula formation, and risk of trochlea injury that can cause diplopia. Lynch Procedure (External Frontoethmoidectomy) This procedure is performed via an external ethmoidectomy approach. The ﬂoor of the frontal sinus is entered. The opening is then widened to include

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Figure 20 CT image (sagittal projection) through the frontal recess. The ‘‘white square’’ indicates the area that is opened during a Lynch procedure and endoscopic approaches to the frontal sinus.

the frontal duct, which is in turn enlarged to establish what is considered an adequate communication with the anterior ethmoid sinus (Fig. 20). The surgery takes one to two hours to perform and aims at achieving permanent drainage and aeration of the frontal sinus. Accordingly, it is indicated to treat symptomatic frontal sinusitis and frontal sinus muco(pyo)celes. The procedure is currently very rarely performed due to a high failure rate. The frontoethmoid opening occludes in up to 50% of cases, leading to recurrent disease and formation of frontal sinus mucoceles (30). In addition, the surgery entails an external incision with the associated cosmetic issues. Lothrop Procedure The Lothrop procedure was originally described as an open approach to treat chronic frontal rhinosinusitis. In this procedure, a common frontal sinus cavity and recess is created by means of removing the bone that divides the left and right sinuses as well as the ﬂoor of the frontal sinus. In addition, a portion of the superior nasal septum is resected. The surgery takes one to two hours to perform. Indications for the Lothrop procedure include the treatment of patients with recurrence of frontal sinusitis despite surgery and to remove frontoethmoid mucoceles, osteomas, or inverting papillomas.

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This procedure fell out of favor because of a high incidence of restenosis with recurrence of frontal sinus disease. Endoscopic Frontal Sinusotomy An endoscopic anterior ethmoidectomy is ﬁrst performed. The frontal recess air cells of the anterior ethmoid are opened to expose the frontal duct (Fig. 21). This area is anterior to the anterior ethmoid artery as it crosses along the roof of the ethmoid sinus and just posterior to the anterior attachment of the middle turbinate. Openings into supra-orbital ethmoid air cells can at times be confused with the frontal duct, which has a more medial and anterior location. When present, agger nasi cells are opened to widen the frontal recess (Fig. 4). What is to be done once the frontal duct is identiﬁed is controversial. Some warn against instrumentation of the duct itself since this can lead to its stenosis. For these surgeons, opening the frontal recess air cells and treating the anterior ethmoid sinus disease is adequate. On the other hand, others recommend widening the duct by either removing part of its inﬂamed mucosa or by drilling the bony walls anteriorly and along the ﬂoor of the frontal sinus with a long handle drill (Fig. 20).

Figure 21 Endoscopic view of the frontal duct and into the frontal sinus following endoscopic frontal sinusotomy.

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In recalcitrant cases of frontal sinusitis or those with ﬁbro-osseous stenosis of the frontal duct/recess, the ﬂoor of the frontal sinus is drilled in addition to the upper nasal septum, which may then be extended to the ﬂoor of the contralateral frontal sinus (modiﬁed Lothrop procedure) (31,32). The newly created opening is at times maintained by placing a stent for four to 12 months following the surgery (33). These cases can usually be performed in about two hours. Perioperative antibiotics are typically used, and postoperative care is similar to that of other endoscopic procedures. Indications for endoscopic frontal sinus surgery include the treatment of patients with chronic frontal sinusitis; to remove frontoethmoid mucoceles, osteomas, or inverting papillomas; or to treat recurrent disease as a salvage procedure for osteoplastic ﬂap operation failures (see following sections) (Fig. 22) (32–36). Most surgeons advocate performing endoscopic frontal sinus procedures with the aid of computer guidance systems (31,34,37). Even so, it should be noted that these procedures involve working extremely close to the anterior cranial fossa, medial orbit, and lacrimal sac; hence, only very experienced surgeons should perform this surgery in order to prevent complications. When they do occur, the complications are typically the same as

Figure 22 CT image (coronal projection) showing soft tissue opacity in the left frontal recess. This patient suffered from recurrent left frontal sinusitis and was successfully treated by an endoscopic frontal sinusotomy.

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those with other endoscopic approaches. Additionally, there appears to be a high incidence of recurrent frontal sinus disease due to restenosis of the frontal recess (31,32,34–37). Like the other endoscopic approaches, the advantages are that there is no incision required and patients recover quickly with minimal postoperative pain. The main disadvantage of the endoscopic approach is that there appears to be a higher recurrence rate with these procedures when compared to the osteoplastic frontal sinus obliteration (see following sections). The area that is opened via the endoscopic approaches, including drilling of the ﬂoor of the frontal sinus, is similar to the one opened by a Lynch or Lothrop procedure (Fig. 20). Hence, there is no reason to expect a higher success rate with the endoscopic approaches compared to the external ones. The success of the endoscopic approach should not be judged until adequate long-term follow-up is conducted, since frontal sinus mucoceles can form more than 10 years following the surgery. Osteoplastic Frontal Sinus Obliteration The osteoplastic frontal sinus obliteration procedure is an effective means to eradicate disease in patients who have recurrent or chronic frontal sinusitis despite attempts at improving drainage via the endoscopic route. The procedure takes about two hours. Additional indications are frontal sinus mucoceles, repair of CSF leaks originating from the posterior wall of the frontal sinus, repair of certain frontal sinus fractures, and repair of frontal sinocutaneous ﬁstula (30,38). Its main rationale is the high failure rate of procedures that aim at opening the frontal recess/duct, hence leading to persistent symptoms and, at times, the formation of mucoceles. Therefore, the frontal sinus is obliterated to circumvent the consequences of an occluded frontal recess. This procedure involves making a skin incision in either the scalp, the mid-forehead, or the eyebrow. The scalp incision that is made above the hairline (bicoronal incision) requires longer operative time and increases intraoperative blood loss but offers superior cosmetics. The supraciliary incision (above the eyebrow) offers more direct access to the frontal sinus and hence reduces operative time and blood loss. However, it is associated with higher incidence of scalp hypesthesia and sometimes long term pain due to transaction of the supratrochlear and supraorbital nerves. The mid-forehead incision offers a compromise. This is made along a skin crease in the forehead and, therefore, has acceptable cosmetics. It also affords direct access to the anterior wall of the sinus with a short operative time and minimal blood loss (38). The bone of the anterior wall of the frontal sinus is then carefully raised in order to open up the sinus. The mucosa of the sinus is completely removed. A large frontal sinus with extensive lateral recesses poses a challenge at removing the entire sinus mucosa. The opening of the frontal duct is then occluded with fascia or other material, such as

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bone wax. Fat is harvested from the abdomen and used to obliterate the sinus cavity. The anterior bony wall is then reﬂected into position. Drains are placed under both the scalp and the abdomen incisions for a few days after the surgery. For this reason, patients typically stay in the hospital as inpatients until the drains come out. Perioperative antibiotics are given and there is no intranasal postoperative care. Sutures are removed within one week. The main advantage to this procedure is that it has a low failure rate (30,38). The disadvantages are that this procedure involves a large incision and is associated with increased length of hospital stay. Permanent frontal scalp hypesthesia may develop, especially following a supraciliary incision since it may transect the supraorbital and supratrochlear nerves. Additional complications include headache, abdominal or scalp wound seroma, hematoma or abscess, headache, dural laceration, and recurrence of disease (33,37). Despite these potential complications, this is a safe and very effective procedure, when done by an experienced surgeon. However, this procedure is not indicated for patients with uncomplicated frontal sinus disease who are undergoing surgery for the ﬁrst time. These patients are better served by endoscopic procedures. ANTIBIOTIC COVERAGE IN PARANASAL SINUS SURGERY: PROPHYLACTIC AND POST SURGERY The role of prophylactic antibiotic coverage in paranasal sinus surgery is controversial (13,14). In addition, there is a lack of consensus regarding antibiotic choice and the duration of such therapy. It is common practice, however, to put patients on antibiotic coverage following sinus surgery for a duration ranging from 48 hours to two weeks. We recommend a 10- to 14-day course. The choice of the antibiotic is dictated by the surgical approach, nature of the disease process, likely bacteria based on published medical literature, and, when available, preoperative or intraoperative bacteriology culture results. The chosen antibiotic should have adequate coverage against skin ﬂora such as Streptococcus spp. and S. aureus and the likely pathogenic bacteria in the involved sinus(es) for surgery via an external approach that require a skin incision. Antibiotic coverage for anaerobic bacteria present in the oral ﬂora is needed for transoral approaches such as Caldwell-Luc procedure. In addition, an antibiotic with demonstrated activity against nasal ﬂora, S. aureus, and likely paranasal sinus pathogens is selected for endonasal approaches, both conventional and endoscopic procedures. The antibiotic of choice should preferably have an easy administration schedule (QD or BID dosing), be well-tolerated, and be available in intravenous as well as equivalent oral formulations. Ability to cross the blood– brain barrier is essential during surgery in patients with periorbital or

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intracranial complications from sinusitis or iatrogenic CSF rhinorrhea (violation of the base of the skull). LASERS AND SINUS SURGERY Presently, lasers have a limited role in sinus surgery. Over the years, various investigators have attempted to use lasers to aid in the eradication of sinus disease. For the most part, these attempts have been somewhat successful; however, the use of lasers is expensive and can be time-consuming. Therefore, the use of lasers has not gained widespread acceptance. The CO2 laser has not been found successful in the treatment of sinus disease. It has a wavelength that gets absorbed by water, and its thermal energy is concentrated with very little spread to the surrounding soft tissues. The principle difﬁculties in applying the CO2 laser to sinus disease treatment is that it requires a relatively dry ﬁeld for hemostasis, it results in signiﬁcant smoke accumulation, and most importantly, its mid-infrared light cannot travel through a ﬁberoptic cable. Thus, tissues must be visualized directly in order to be treated with the CO2 laser (39). In contrast, the Nd:YAG, KTP/532, Argon, and Ho:YAG lasers can be carried through ﬁberoptic cables. Fiberoptic threads can be passed into instruments, that are designed for intranasal use. Hence, the instruments that transmit the laser energy can be handled manually and placed directly onto tissues with ease and precision. Each of these has advantages and disadvantages related to depth of penetration, scatter of thermal energy, and their ability to coagulate small blood vessels. These lasers have been used to treat inferior turbinate hypertrophy with moderate success (39). They can also be used to remove nasal lesions, such as nasal papillomata, pyogenic granuloma, and other small superﬁcial lesions (40). A common application of laser technique is the treatment of hereditary hemorrhagic telangiectasias. This is an autosomal-dominant disease characterized by telangiectatic lesions primarily in mucosalized areas, such as the nose, mouth, and gastrointestinal tract. These patients often suffer from severe bouts of epistaxis throughout their lives. The Nd:YAG and KTP/ 532 lasers have each been used successfully to ablate these lesions (39–43). Patients often require retreatment, however, every four to six months. Ho:YAG laser with its capability to vaporize bone has been used in intranasal endoscopic dacryocystorhinostomy. It did not gain widespread popularity since it does not offer any signiﬁcant advantage over using cold instruments to justify the added cost and operative time. CONCLUSION Paranasal sinus surgery has several indications; the most common is CRS that failed medical therapy. The approach and extent of surgery is dictated

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by the nature of the disease and the involved sinuses. Endoscopic approaches that are made possible with the technological advances in ﬁberoptics have gained widespread use. They offer a minimally invasive technique that has a low morbidity and high success rate for treating inﬂammatory paranasal sinus pathology. The surgery is not risk free, however. Image guidance systems can make the surgery safer. Surgery is often an adjunct to medical therapy. A better understanding of the pathogenesis of rhinosinusitis allows for better delineation of the role of medical therapy and surgery. REFERENCES 1. Kennedy DW, Zinreich SJ, Rosenbaum AE, Johns ME. Functional endoscopic sinus surgery. Theory and diagnostic evaluation. Arch Otolaryngol 1985; 111:576–582. 2. Rice DH. Indications for endoscopic sinus surgery. Ear Nose Throat J 1994; 73:461–464, 466. 3. Messerklinger W. Background and evolution of endoscopic sinus surgery. Ear Nose Throat J 1994; 73:449–450. 4. Stammberger H. The evolution of functional endoscopic sinus surgery. Ear Nose Throat J 1994; 73:451, 454–455. 5. Vining EM, Kennedy DW. The transmigration of endoscopic sinus surgery from Europe to the United States. Ear Nose Throat J 1994; 73:456–458, 460. 6. Kennedy DW. Functional endoscopic sinus surgery. Technique. Arch Otolaryngol 1985; 111:643–649. 7. Messerklinger W. On the drainage of the normal frontal sinus of man. Acta Otolaryngol 1967; 63:176–181. 8. Stammberger H, Hasler G. Functional Endoscopic Sinus Surgery: The Messerklinger Technique. St Louis, MO: Mosby, 1991. 9. Catalano PJ. Minimally invasive sinus technique: what is it? Should we consider it? Curr Opin Otolaryngol Head Neck Surg 2004; 12:34–37. 10. Kieff DA, Busaba NY. Non-dental related isolated chronic maxillary sinus opaciﬁcation does not correlate with ipsilateral intranasal structural abnormalities. Ann Otol Rhinol Laryngol 2004; 113:474–476. 11. Taylor MJ, Ponikau JU, Sherris DA, Kern EB, Gaffey TA, Kephart G, Kita H. Detection of fungal organisms in eosinophilic mucin using a ﬂuorescein-labeled chitin-speciﬁc binding protein. Otolaryngol Head Neck Surg 2002; 127: 377–383. 12. Ferguson BJ. Categorization of eosinophilic chronic rhinosinusitis. Curr Opin Otolaryngol Head Neck Surg 2004; 12:237–242. 13. Annys E, Jorissen M. Short term effects of antibiotics (Zinnat) after endoscopic sinus surgery. Acta Otorhinolaryngol Belg 2000; 54(1):23–28. 14. Hasselgren PO, Ivarsson L, Risberg B, Seeman T. Effects of prophylactic antibiotics in vascular surgery. A prospective, randomized, double-blind study. Ann Surg 1984 Jul; 200(1):86–92. 15. Gross CW, Gross WE. Post-operative care for functional endoscopic sinus surgery. Ear Nose Throat J 1994; 73:476–479.

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16. Stankiewicz JA. Complications of endoscopic sinus surgery. Otolaryngol Clin North Am 1989; 22:749–758. 17. Parikh SR, Fried MP. Navigational systems for sinus surgery: new developments. J Otolaryngol 2002; 31(suppl 1):S24—S27. 18. Metson R. Image-guided sinus surgery: lessons learned from the ﬁrst 1000 cases. Otolaryngol Head Neck Surg 2003; 128:8–13. 19. Metson R, Gliklich RE, Cosenza M. A comparison of image guidance systems for sinus surgery. Laryngoscope 1998; 108(8 Pt 1):1164–1170. 20. Fried MP, Kleeﬁeld J, Gopal H, Reardon E, Ho BT, Kuhn FA. Image-guided endoscopic surgery: results of accuracy and performance in a multicenter clinical study using an electromagnetic tracking system. Laryngoscope 1997; 107:594–601. 21. Selivanova O, Kuehnemund M, Mann WJ, Amedee RG. Comparison of conventional instruments and mechanical debriders for surgery of patients with chronic sinusitis. Am J Rhinol 2003; 17:197–202. 22. Bernstein JM, Lebowitz RA, Jacobs JB. Initial report on postoperative healing after endoscopic sinus surgery with the microdebrider. Otolaryngol Head Neck Surg 1998; 118:800–803. 23. Busaba NY, Salman SD. Maxillary sinus mucoceles: clinical presentation and long-term results of endoscopic surgical treatment. Laryngoscope 1999; 109:1446–1449. 24. Busaba NY, Kieff DA. Endoscopic sinus surgery for inﬂammatory maxillary sinus pathology. Larynogoscope 2002; 112:1378–1383. 25. Goodman WS. The Caldwell-Luc procedure. Otolaryngol Clin North Am 1976; 9:187–195. 26. Schaefer SD, Gustafson RO, Bansberg SF. Sinus surgery. In: Bailey BJ, Calhoun KH, eds. Head and Neck Surgery—Otolaryngology. 3rd ed. Philadelphia, PA: Lippincott Williams and Wilkins, 2001:359–370. 27. Weber R, Keerl R, Draf W. Endonasal endoscopic surgery of maxillary sinus mucoceles after Caldwell-Luc operation. Laryngorhinootologie 2000; 79: 532–535. 28. Busaba NY, Salman SD. Ethmoid mucocele as a late complication of endoscopic ethmoidectomy. Otolaryngol Head Neck Surg 2003; 128:517–522. 29. Kieff DA, Busaba NY. Treatment of isolated sphenoid sinus inﬂammatory disease by endoscopic sphenoidotomy without ethmoidectomy. Laryngoscope 2002; 112:2186–2188. 30. Hardy JM, Montgomery WW. Osteoplastic frontal sinusotomy: an analysis of 250 operations. Ann Otol Rhinol Laryngol 1976; 85(4 Pt 1):523–532. 31. Wormald PJ, Ananda A, Nair S. Modiﬁed endoscopic Lothrop as a salvage for the failed osteoplastic ﬂap with obliteration. Laryngoscope 2003; 113: 1988–1992. 32. Stankiewicz JA, Wachter B. The endoscopic modiﬁed Lothrop procedure for salvage of chronic frontal sinusitis after osteoplastic ﬂap failure. Otolaryngol Head Neck Surg 2003; 129:678–683. 33. Neal DG. External ethmoidectomy. Otolaryngol Clin North Am 1985; 18:55–60. 34. Kountakis SE, Gross CW. Long-term results of the Lothrop operation. Curr Opin Otolaryngol Head Neck Surg 2003; 11:37–40.

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35. Gross CW, Harrison SE. The modiﬁed Lothrop procedure: indications, results, and complications. Otolaryngol Clin North Am 2001; 34:133–137. 36. Casiano RR, Livingston JA. Endoscopic Lothrop procedure: the University of Miami experience. Am J Rhinol 1998; 12:335–339. 37. Samaha M, Cosenza MJ, Metson R. Endoscopic frontal sinus drillout in 100 patients. Arch Otolaryngol Head Neck Surg 2003; 129:854–858. 38. Montgomery WW. State-of-the-art for osteoplastic frontal sinus operation. Otolaryngol Clin North Am 2001; 34:167–177. 39. Rathfoot CJ, Duncavage J, Shapshay SM. Laser use in the paranasal sinuses. Otolaryngol Clin North Am 1996; 29:943–948. 40. Shah RK, Dhingra JK, Shapshay SM. Hereditary hemorrhagic telangiectasia: a review of 76 cases. Laryngoscope 2002; 112:767–773. 41. Parkin JL, Dixon JA. Laser photocoagulation in hereditary hemorrhagic telangiectasia. Otolaryngol Head Neck Surg 1981; 89:204–208. 42. Levine HL. Lasers in endonasal surgery. Otolaryngol Clin North Am 1997; 30:451–455. 43. Levine HL. Endoscopy and the KTP/532 laser for nasal sinus disease. Ann Otol Rhinol Laryngol 1989; 98(1 Pt 1):46–51.

13 Complications of Acute and Chronic Sinusitis and Their Management Gary Schwartz and Steve White Vanderbilt University Medical Center, Nashville, Tennessee, U.S.A.

INTRODUCTION Sinusitis is a common condition that is usually treated uneventfully on an outpatient basis. Admission to a hospital is rare, as are the complications stemming from sinusitis (Table 1). Although not exactly known, the incidence of complications from sinusitis is thought to be low. One study found a 3% incidence of complications in hospitalized patients (1). In addition,

Table 1 Complications of Sinusitis Local complications Mucocele Osteomyelitis (Pott’s puffy tumor) Orbital complications Inﬂammatory edema Orbital abscess Subperiosteal abscess Cavernous sinus thrombosis Intracranial complications Meningitis Subperiosteal abscess

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other studies from referral centers looking at complications only report a few patients per year (2). The rarity of this problem can make physicians complacent about looking for complications and therefore could lead to signiﬁcant morbidity and mortality. Morbidities can include blindness and neurologic deﬁcits. Complications from sinusitis are caused by the spread of bacteria from the sinus to the surrounding structures. There are two means by which the spread of infection can occur. The most common route is through direct spread to contiguous areas. The spread of infection occurs through either neurovascular foramina, a defect in the sinus wall from a fracture because of trauma, or a congenital abnormality. Spread of infection to the bony wall can also lead to erosions creating an opening through which infection can progress. PATHOPHYSIOLOGY Hematogenous route is the other route for an infection to spread. Either bacteria or septic emboli can get into the bloodstream and reach intracranial sites separated by a distance from the sinus. To some extent, all sinus veins drain intracranially and, therefore, have the potential to spread bacteria to the brain. The frontal sinus, whose venous drainage is almost entirely intracranial, is the most common origin for bacterial spread which can cause intracranial complications. Venous drainage from the sinus runs via the diploic veins that penetrate the bony sinus lining. The inner table diploic veins drain directly into the dural venous plexuses and later into the sagital sinus. The outer table of the sinus drains into both the venous plexuses of the face, which then drain through the ophthalmic veins in the orbits, and the dural sinuses. Bacteria from facial skin infections take the same path, which can lead to intracranial infections. Also draining into the dural sinuses are the cortical veins from the brain parenchyma. As these veins are without valves, blood can ﬂow either antegrade or retrograde. Therefore, septic emboli can start in a frontal sinus, drain into a dural sinus, and ﬂow retrograde into the brain, leading to an abscess. Septic emboli can also seed structures along the drainage path, leading to an epidural or subdural empyema. LOCAL COMPLICATIONS Osteomyelitis A sinus infection can spread to the surrounding bony structures leading to osteomyelitis of either the anterior or posterior walls of the sinus. The spread of infection can be either by direct extension or by valveless veins draining into the sinus. Osteomyelitis is most commonly observed in the walls of the frontal sinuses. Once the bone has become infected, it can erode, allowing the infection to spread under the subperiostium leading to subperiosteal

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abscess formation. The erosion can affect either the anterior or posterior tables of the sinus, leading to either extracranial or intracranial extension. If the subperiosteal abscess is adjacent to the anterior table of the frontal bone, it is called Pott’s puffy tumor after Sir Percival Potts, who ﬁrst described this condition. This is an extremely rare diagnosis with only 20 cases in the literature (3). Patients with Pott’s puffy tumor are always older than six years because the frontal sinus is not pneumatized until this age. Etiology Osteomyelitis of the bone overlying the sinus is caused by the same organisms that cause sinusitis. The most common are Staphylococcus, Streptococcus, and anaerobic bacteria (3,4). Clinical Presentation Patients who present with osteomyelitis as a complication of sinusitis frequently present with complaints similar to patients with simple sinusitis. These include headache, photophobia, and fever. If Pott’s puffy tumor is present, there will also be swelling in the forehead. Diagnosis Diagnosis requires radiographic imaging not only to conﬁrm, but also to rule out any associated intracranial complications. Imaging is most easily accomplished with a CT scan. Routine blood tests such as complete blood cell counts are of little value as they are very nonspeciﬁc, but an elevated sedimentation rate may be an indication of osteomyelitis. Treatment Treatment for osteomyelitis is by administering intravenous antibiotics for a prolonged period of time, six to eight weeks. The antibiotics chosen need to cover both anaerobic and aerobic organisms. An appropriate empiric choice is a combination of a third-generation cephalosporin (i.e., ceftriaxone) and metronidazole or clindamycin, with consideration given to adding vancomycin or linezolid (also available orally), if there is a signiﬁcant Streptococcus pneumoniae antimicrobial resistance or the involvement of Staphylococcus spp. Oral therapy with amoxicillin–clavulanate or the combination of ceﬁxime and metronidazole or clindamycin are also appropriate. The choice of therapy should be adjusted according to adequate cultures. If an abscess is present, surgical drainage is the treatment of choice. Mucocele A mucocele is a chronic, cystic lesion of the paranasal sinuses. It grows slowly, taking years to become symptomatic, and the symptoms are typically related to the increasing size of the mucocele. As it enlarges, it can exert pressure on the

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sinus wall which leads to bony erosion. After eroding through the sinus wall, the mucocele can extend into surrounding structures. Mucoceles most frequently involve the frontal sinus, followed by the ethmoid and maxillary sinuses (5). Symptomatic frontal or ethmoid sinus mucoceles can cause headaches, diplopia, and proptosis. The proptotic globe is typically displaced downward and outward. Maxillary sinus mucoceles are usually an incidental ﬁnding on radiographs of the sinus. Mucoceles in this location rarely cause symptoms because the maxillary sinuses are large and the mucoceles rarely become large enough to cause bony abnormalities. Maxillary sinus mucoceles can become symptomatic, if they obstruct the ostium of the maxillary sinus. Mucoceles can also become symptomatic in any sinus when they become infected, forming mucopyocele. Diagnosis is usually made by CT of the sinuses. Symptomatic mucoceles are treated with surgical removal and possible sinus obliteration. ORBITAL INFECTIONS Orbital infections can be caused by penetration of the orbit during either surgery or trauma; most frequently the result of a bacterial spread is from an infected sinus. As the orbit is bordered by several sinuses—the frontal, ethmoid, and maxillary—infection from any of these sinuses can potentially spread to the orbit. The ethmoid sinus is almost exclusively implicated in the spread of infection to the orbit. This is related to the thickness of the sinus wall lining the orbit. The thinner the wall, the easier is for infection to spread through it. The ethmoid sinus has the thinnest wall, the lamina papyracea, which lines the lateral wall of the sinus and the medial wall of the orbit. Most orbital infections are, therefore, on the medial side of the orbit. Although much less common, the thicker wall sinuses can also be the source of an orbital infection. Once infection has spread past the sinus wall, the periosteal lining of the sinus wall serves as an additional barrier to protect the orbit from the spread of the infection. If an abscess forms between the wall and periosteum, it is called a subperiosteal abscess. If the periosteum is violated, then an orbital abscess may form. Etiology Many organisms can be isolated in patients with orbital infections (Table 2). These may be single or multiple organisms, anaerobic or aerobic organisms, or mixture of both. Frequently, the isolates are the same as those found in the infected sinus. To best determine the type of organism, patients should be divided into two groups. The ﬁrst group consists children of under 9 years old. These patients typically have single aerobic organisms, which include alpha and beta hemolytic Streptococcus spp., Staphylococcus spp., nonHaemophillus inﬂuenzae, and Moroxalla catarrhalis (6). The second group

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Table 2 Common Organisms Isolated from Patients with Orbital Infections Aerobic bacteria Streptococcus spp.: Streptocococcus pneumoniae, Streptococcus viridans, and Streptococcus viridans Staphylococcus spp.: Staphylococcus aureus, and Staphylococcus epidermidis Haemophilus inﬂuenzae Moraxella catarrhalis Anaerobic bacteria Gram-negative bacilli (Prevotella, Porphyromonas, and Bacteroides spp.) Veillonella parvula Peptostreptococcus spp. Fusobacterium spp. Proprionibacterium spp. Immunocompromised hosts Pseudomonas aeruginosa Fungal species: aspergillosis, and mucormycosis

of patients is over nine years old, and typically have complex infections with mixed aerobic and anaerobic organisms. This is especially true for patients in their teens or older. Although aerobic organisms are frequently the same as those found in younger children, the anaerobic organisms are usually oral ﬂora such as anaerobic gram-negative bacilli, Peptostreptococus spp., Fusobacterium spp., and Veillonella parvule. These rules are not absolute, as there are reports of anaerobic bacteria isolated in young children (7,8). There are several theories that explain the causes of this transition; they include the increased incidence of chronic infections in older children and adults and the relative size of the osteo meatal opening. The relative size of the osteo meatal opening to the sinus cavity is larger in younger individuals compared to that of older ones and therefore less likely to become occluded. Occlusion of the opening blocks the sinus cavity, which becomes anaerobic and promotes the growth of anaerobic organisms. Diagnosis In an article, Chandler described a classiﬁcation system for orbital infection that still in use today (9) (Table 3, Fig. 1). The spectrum of orbital infections is classiﬁed into ﬁve groups; each represents a progressively more serious infection. Group 1 is preseptal cellulitis, a simple cellulitis of the eyelids which manifests as swelling of the eyelids. Infection is limited to the skin in front of the orbital septum. Group 2 is orbital cellulitis, seen as diffuse edema of the lining of the orbits. It manifests as eyelid swelling and pain with extraocular muscle movement. Group 3, subperiosteal abscess, is characterized by edema of the orbital lining with a collection of ﬂuid below the

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Table 3 Chandler Classiﬁcation Group Group Group Group Group

1: 2: 3: 4: 5:

Periorbital cellulitis Orbital cellulitis Subperiosteal abscess Orbital abscess Cavernous sinus thrombosis.

Source: From Ref. 9.

periosteum usually involving the medical wall of the orbit. Clinically patients with this condition are similar to Group 2 but proptosis may also be noted. Group 4, orbital abscess, is characterized as a true abscess in the orbital space. This may manifest with proptosis, impaired eye movement, and in the worse case, blindness. Group 5 is cavernous sinus thrombosis with rapidly progressive bilateral chemosis, ophthalmoplegia, retinal engorgement, and loss of visual acuity, along with possible meningeal signs and high fever. The most important decision in dealing with a patient with a swollen eye is determining whether a preseptal or orbital process exists. Obtaining a thorough history, physical examination, and potentially imaging studies can very often assist in this. Preseptal cellulitis is most often caused by local trauma. The history may reveal an insect bite or other trauma to the skin around the eye, which becomes secondarily infected. This infection is usually insidious in onset. H. inﬂuenzae type B infection causes rapid eyelid swelling and eyelid closure within hours. With the advent of the H. inﬂuenzae type B

Figure 1 (1) Preseptal cellulitis, (2) Orbital cellulitis, (3) Subperiosteal abscess, (4) Orbital abscess, and (5) Cavernous sinus thrombosis. Source: From Ref. 49.

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vaccine, a hematogenous source of infection very rarely is identiﬁed as the cause of preseptal cellulitis (10). Patients with H. inﬂuenzae infection typically develop rapid eyelid swelling with eyelid closure within hours. As preseptal cellulitis is an inﬂammatory process, evidence of local eye inﬂammation is present. Findings include warmth, redness, induration, and pain with palpation. In patients with red swollen eyelids which are boggy, painless to palpation, and not indurated, an allergic reaction or venous congestion because of an underlying sinusitis should be considered. Regardless of the cause of preseptal cellulitis, there should be no visual problem, no proptosis, or no signiﬁcant pain with eye movement. Orbital infections (group 2–4) are harder to identify and are typically more insidious in onset. Patients frequently show a history of nasal drainage, headache or pressure, and fever. If infection is in the orbit, visual loss may be present. Orbital infections may present in a similar way to preseptal infections. These patients present with evidence of orbital inﬂammation. The presence of eyelid swelling is not indicative of inﬂammation. As space is limited in the orbit, any inﬂammatory mass could impact the surrounding structures. A simple orbital infection exerts pressure on the ocular muscles and causes pain with eye movement. If a subperiosteal abscess or abscess forms, there may be pressure placed on the orbit causing proptosis. If the inﬂammatory process pushes on the optic nerve, blindness may result. Early on, the ﬁndings of orbital infection may be minimal, but become more apparent if the infection is allowed to progress. Imaging As there can be an overlap in the symptoms of orbital infection, preseptal cellulitis, and other causes of eyelid swelling, some clinicians recommend imaging in all patients with a swollen eye. However, a more common approach would be to reserve imaging studies for those with nonclassic presentations of preseptal cellulitis and those with presumed preseptal cellulitis, who do not improve following one to two days of treatment. All patients with evidence of orbital cellulitis need an imaging study. The most frequently used imaging study is a CT scan, with or without contrast, using thin slices through the orbit with coronal and axial images. A CT scan is highly sensitive in documenting these infections. Patients with preseptal cellulitis show evidence of eyelid swelling without orbital involvement. The CT scan images of patients with Chandler group 2 (orbital cellulites) frequently show an opaciﬁed ethmoid sinus with an ill-deﬁned mass on the orbital side of the lamina papyracea (Fig. 2). In addition, there may also be inﬂammation of the rectus muscle. This is the mildest and most common type of orbital infection (Fig. 3). Group 3 (subperiosteal abscess) shows evidence of inﬂammation with periosteum elevation and rim enhancement, rectus muscle displacement,

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Figure 2 Ethmoid sinusitis with inﬂammation of the medial wall of the right orbit.

and if large enough, some degree of proptosis of the eye (Fig. 3). Findings for group 4 (orbital abscess) show inﬂammatory material in the orbital space with proptosis. An MRI is possibly a better type of imaging study, but can be problematic since most orbital infections are in young children who will need sedating for the procedure. An MRI is best reserved for the complicated infection with intracranial extension, such as cavernous sinus thrombosis (group 5) or epidural abscess. There is no value in obtaining plain radiographs of the sinuses to diagnose an orbital infection.

Figure 3 Ethmoid sinusitis with subperiosteal abscess in an adolescent who presented to an emergency department with eyelid swelling and pain with eye movement.

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Treatment Until the past few years, there has been much disagreement on how to treat orbital infections. Until recently, surgical drainage was thought to be necessary in the majority of patients. Now medical management is the treatment of choice in the majority of patients with this type of infection. To successfully treat patients with orbital infections, the patients are to be stratiﬁed into low and high risk groups based on likelihood of complications. Low risk patients have over 90% cure rate with antibiotic therapy alone (11). Low risk patients are those under 9 years old, who most likely have single aerobic organisms causing the infection. In addition to young age, low risk patients must also have no visual compromise, at most a modest-sized subperiosteal abscess on the medial side of the orbit, and no evidence of intracranial infection (Table 4). They also must be able to cooperate with frequent ophthalmologic examinations. How frequently an exam must be repeated is not known. Published studies recommend ophthalmic examinations from once a day to multiple times a day (11,12). The antibiotics selected should be able to cover aerobic gram-positive cocci. Adequate choices include a third-generation cephalosporin (ceftriaxone or cefotaxime) unless there is a high likelihood of recovery of resistant S. pneumoniae. In these cases, vancomycin should be given. As anaerobic organisms are rarely seen in young patients, administering antibiotics that cover these organisms is probably unnecessary. Generally, treatment includes less than a week of parenteral antibiotics and is followed by a prolonged period of two to three weeks of oral antibiotic such as high dose of ampicillin/clavulanic acid (90 mg/kg/day in children and 4 g/day in adults) (13,14). In addition to antibiotics, all patients should be started on a nasal decongestant, such as oxymetazoline. Most patients who ﬁt into this low risk category respond appropriately with only antibiotic treatment. However, if the patient’s condition deteriorates, it may be necessary to have the abscess and sinus drained. Indications for surgery in this low risk group include visual loss, afferent papillary defect, fever after 36 hours of antibiotic treatment, or absence of clinical improvement after 72 hours. There is no indication for repeating the CT scan when deciding whether to perform surgery or not. Findings on the CT scan

Table 4 Low Risk Group for Complications Age under 9 years old No visual compromise At most, modest-size abscess on medial side of orbit No evidence of intracranial complication Ability to cooperate with serial ophthalmologic exams Not immunocompromised

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may worsen before they improve, even in patients who are responding appropriately to antibiotics. Young children who are not likely to be cured by antibiotics alone include those with subperiosteal abscess not on the medial side of the orbit and those with over 2 mm of proptosis (14). A more aggressive approach is needed to treat older children and adults, as they have more complex infections that are not as reliably treated with antibiotics alone. Recommended antibiotics for complex infections are a second-generation cephalosporin that covers anaerobic and anaerobic organisms (i.e., cefoxitin or cefotetan), clindamycin, or ampicillin/sulbactam. Other combinations of antibiotics, such as penicillin and metronidazole, can also be used as long as they cover both aerobic and anaerobes. If there is a high likelihood of recovering resistant S. pneumoniae vancomycin can be added. Even with the administration of appropriate antibiotics, cultures from an infected sinus or orbital abscess frequently can still grow organisms after several days of therapy. Until the abscess or infected sinus is sterile, there is a risk of the infection spreading. For these patients, a trial of antibiotic therapy alone can be given, but it will likely not cure the infection and place the patient at a continued risk for complications. Some clinicians will wait for 24 hours to see how these patients with complex infections respond, whereas others will proceed to urgent surgery to drain the abscess along with administering parenteral antibiotics. Surgery can be done either endoscopically or through an open approach, depending on the location of the subperiosteal abscesses and the physician’s preference.

INTRACRANIAL COMPLICATIONS OF SINUSITIS Introduction Intracranial complications of sinusitis are rare, occurring one to three times per year in major referral centers (15–23). Undoubtedly, the advent of antibiotic therapy has decreased the incidence of intracranial infectious complications of sinusitis. Over the three decades spanning 1950–1980, Bradley et al. (24) noted a four-fold decrease in intracranial abscess arising from sinus infection, despite improvements in diagnostic modalities which would otherwise have increased the number of diagnosed cases. Yet, because these intracranial infections represent the most lethal consequences of diagnostic or treatment failure of sinusitis, it is imperative for clinicians to understand the clinical presentation, diagnostic options, and therapeutic approach to treat each of these entities. Intracranial complications of sinusitis include: (1) meningitis, (2) epidural abscess, (3) subdural abscess, (4) brain abscess, and (5) dural sinus thrombosis. In contrast to intraorbital infections, sinusitis underlies only 3% to 9% of suppurative intracranial infections (15–17,20) and is responsible for less than 1% of cases of meningitis (17).

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However, extra-axial abscesses (subdural and epidural) as discrete entities are most commonly of sinogenic origin, and epidural abscess is the most common intracranial complication from sinusitis in some series (15,16,21), although meningitis is more common in other series (23). Meningitis may be under-represented as lumbar puncture is to be avoided in the setting of intracranial space-occupying lesions and would likely only be performed when a CT or MRI scan fails to demonstrate an intracranial abscess or when an intracranial abscess is not considered. Conversely, concomitant sinusitis may fail to be diagnosed in patients diagnosed with meningitis if a neuro-imaging study is not performed, a likelihood in the management of many patients diagnosed with meningitis. Dural venous sinus thrombosis/thrombophlebitis (sagittal, transverse, and cavernous) is the least common complication, absent in some case series (16,19), and accounting for 3% to 9% of intracranial complications in others (15,18,23). In most cases, venous sinus thrombosis is not an isolated complication, but occurs in concert with subdural suppuration. Patients commonly have more than one intracranial complication, such as epidural/subdural abscess in association with cerebral abscess and/or meningitis. Table 5 summarizes the relative frequency of each intracranial complication from data pooled from several recent studies that used similar inclusion criteria and selection methods. Most studies have demonstrated a large male predominance (greater than 3:1, male/female) for intracranial suppuration from sinusitis (16–20,22). This male predominance remains unexplained, but prevails at all age groups and may suggest sex-related anatomical differences in sinus structure/sinus venous drainage. Pathogenesis The pathogenesis for intracranial suppuration mirrors that of intraorbital infection. Intracranial infection can develop following direct extension through sinus wall invasion to contiguous bone, and then to intracranial Table 5 Relative Frequency of Intracranial Complicationsa Intracranial complication Meningitis Brain abscess Epidural abscess Subdural abscess Dural sinus thrombosis Percent of patients with >1 intracranial complication

Relative frequency (%, range) 34% (14–54) 27% (0–50) 23% (0–44) 24% (9–86) 8% (0–27) 28%

Note: Study reference 30 excluded meningitis cases as a complications. a Pooled data from 131 patients in eight studies (15–17,19,20,23,30,48).

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structures through either osteitis or congenital or traumatic defects. In contrast to orbital infections, the more common method of intracranial suppurative spread is by the propagation of septic emboli via calvarial diploic veins and the valveless venous system responsible for drainage of the midface and paranasal sinuses (15,16,20,23). Although many of these complications arise in the setting of pansinusitis, some intracranial infections are more strongly associated with speciﬁc sinus involvement. Meningitis often arises from ethmoid or sphenoid sinus involvement (23). Cavernous sinus thrombosis is also associated with sphenoiditis and ethmoiditis (25,26), although it was more commonly associated with frontal sinusitis prior to use of current antibiotic regimens (25). The frontal sinuses are most frequently implicated in the development of extra-axial and intracerebral abscesses as well as infection of the remaining dural sinuses (15,16,21,23). Clinical Presentation Because of the shared pathogenic origin, it common for a patient to have more than one intracranial complication. Therefore, it is difﬁcult to attribute a presenting symptom to an isolated intracranial cause. Similarly, the signs and symptoms of rhinosinusitis also overlap to some degree with the presentation of intracranial infection. Common presenting features will be discussed in this section, and speciﬁc presentations more common or unique to a particular intracranial pathological entity will subsequently be discussed. Table 6 summarizes presenting symptoms and signs, collated from recent studies with similar inclusion criteria. Headache, commonly frontal or retro-orbital, is the overwhelmingly prominent symptom, occurring in approximately 70% of patients with intracranial infection arising from sinusitis. Most patients have fever (>38.5 C) as well. As would be expected, many patients have symptoms of sinonasal disease with purulent rhinorrhea and sinus pressure/pain. Compared to adults, Table 6 Presenting Symptoms/Signs of Intracranial Infection Arising from Sinusitisa Headache (%) Fever (%) Altered mental status (ranging from confusion to obtundation; %) Nausea/vomiting (%) Cranial nerve palsy (%) Seizure (%) Other focal neurologic signs (hemiparesis/hemiplegia, aphasia, ataxia, motor/sensory deﬁcits; %) Nuchal rigidity (%) a

Pooled data from 91 patients in seven studies (15–17,19,20,30,48).

69 60 41 30 18 14 14 10

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children rarely have prominent rhinorrhea or upper respiratory symptoms, and complications often arise during a more acute course of sinusitis. Patients also commonly have symptoms of increased intracranial pressure, including alterations in mental function, vomiting, and photophobia. Arachnoid irritation may be indicated by nuchal rigidity (15–17,19,20). Later neurological symptoms and signs for intracranial infections include seizures, focal paresis, and cranial nerve palsies. Diagnosis Prior to the advent of computerized cross-sectional neuro-imaging (CT and MRI), diagnosis of space-occupying intracranial infections was primarily based on clinical evaluation and judgment (22). CT and MRI scans are complementary techniques, each of which can yield diagnostic information helpful in the deﬁnitive management of intracranial complications. CT scan is readily available, can demonstrate most cases of intracranial suppuration, and is a technique of choice to evaluate bony involvement. CT scanning is the imaging modality of choice for initial evaluation of complications from sinusitis and for planning sinus surgery because of its superior ability to delineate air–bone and air–soft tissue interfaces. MRI, on the other hand, has better resolution for intracranial pathology and has higher diagnostic accuracy for intracranial infections. In one study comparing CT and MRI for the diagnosis of suppurative complications from sinusitis, CT scan was diagnostic for 36 of 39 cases (92%) compared to 100% with MRI. MRI was also able to detect meningitis in 14 cases compared to three for CT scan. CT scanning missed one subdural abscess and one intracerebral abscess. Both modalities exceeded diagnoses made on clinical grounds, which had an accuracy of 82% overall (22). Contrasted CT scan may be contraindicated in patients with renal insufﬁciency or those with life-threatening contrast allergies. MRI should be employed as the ﬁrst method of evaluation in such cases. If such patients are unsuitable for MRI because of implanted ferromagnetic devices, pacemakers, implanted deﬁbrillators, or other contraindications, patients with renal insufﬁciency may gain some nephro-protective effect from the administration of n-acetyl cysteine (27) or from hydration with sodium bicarbonate (28) prior to contrast administration. Meningitis Clinical Presentation Meningitis most frequently presents as headache. The majority of patients also have fever (>38.5 C) and more than half have neck stiffness/nuchal rigidity. Other symptoms include vomiting, mental status changes, and less

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commonly, seizures (15,16,20,29). In one series, a patient presented with facial nerve palsy (30). Bacteriology As with other sources for bacterial meningitis, S. pneumoniae is the most common organism causing meningitis in the setting of sinusitis. Another causative organism, in order of decreasing incidence, is S. aureus (especially in sphenoid sinusitis). Rarely, isolates include H. inﬂuenzae, Neisseria meningitidis, and gram-negative aerobic bacilli (29). The primary pathogen in patients with AIDS is Cryptococcus neoformans (29). Diagnosis Although meningitis is routinely diagnosed by lumbar puncture and cerebrospinal ﬂuid analyses, the performance of lumbar puncture in the setting of a space-occupying lesion risks trans-tentorial uncal herniation, particularly when the mass is in the temporal fossa (31). As signs and symptoms of spaceoccupying infection can be subtle or be obscured by the ﬁndings that suggest meningitis, CT scan should be obtained prior to lumbar puncture when sinusitis has been diagnosed or clinically suspected. When suspected or known, space-occupying infection (abscess) or increased intracranial pressure precludes lumbar puncture; diagnosis of meningitis can sometimes be made on the basis of contrast-enhanced magnetic resonance imaging. Younis found MRI diagnostic in 14 of 21 patients with meningitis-complicating sinusitis; CT was diagnostic in 3 of 21 patients (22). Contrast-enhanced MRI typically demonstrates dural enhancement along the falx cerebri, tentorium, and dural convexity. Conversely, CT and unenhanced MRI are usually normal, with the exception of ﬁndings of sinusitis (22). Treatment Isolated meningitis, conﬁrmed by absence of space-occupying lesions on CT scanning or MRI, is treated exclusively with antibiotics. As meningitis can progress rapidly in a fulminating course, especially with the predominance of pneumococcus as the primary pathogen, antibiotic therapy should be initiated as soon as the diagnosis is suspected and prior to neuro-imaging or lumbar puncture (32). Blood culture, on the other hand, should be obtained prior to the administration of antibiotics, as blood collection will not delay therapy. S. pneumoniae meningitis has a case fatality rate of 20% with signiﬁcant morbidity among survivors (33). Dexamethasone, when administered either before or with ﬁrst antibiotic dose, has been shown to decrease unfavorable outcome and mortality (34,35). On the other hand, because vancomycin will only reach the cerebrospinal ﬂuid (CSF) through inﬂamed meninges, administration of dexamethasone may decrease CSF antibiotic penetration (36). In areas with high prevalence of antibiotic-resistant S. pneumoniae, one must

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weigh the potential decrease in sequellae with the possibility of decreased antibiotic efﬁcacy. Dexamethasone may also be warranted for treatment of cerebral edema secondary to intracranial infection; however, steroid therapy may also contribute to immunosuppression and its role in intracranial suppuration, exclusive of isolated meningitis, has not been rigorously studied. Choice of initial antibiotic therapy consists of a parenteral third-generation cephalosporin (cefotaxime or ceftriaxone) combined with vancomycin to cover resistant S. pneumoniae. Further reﬁnement of antibiotic choice should then be made upon review of CSF gram stain and again after results of CSF culture. In patients with AIDS and contraindication for lumbar puncture, one would need to initiate intravenous therapy with amphotericin B to cover cryptococcus. Brain Abscess Clinical Presentation Headache and fever are the initial prominent symptoms. Moreover, nausea and vomiting are also frequent. Altered mental status—including confusion, decreased mentation, and/or behavioral changes—is an alarming symptom which should be a tip-off that a serious intracranial process is occurring beyond sinusitis or other causes of fever and headache. Intracerebral abscess, in particular, may be associated with behavioral changes, secondary to associated cerebritis. As the majority of brain abscesses from sinusitis occur in the frontal lobes, relatively neurologically silent, these mental status changes may be subtle and unlikely to be associated with focal neurologic deﬁcits (20). Intracerebral abscess also presents a signiﬁcant risk for seizure development. Bacteriology Intracranial and extra-axial abscesses often yield multiple organisms, both aerobic and anaerobic, including Fusobacterium spp., anaerobic gram-negative bacilli (Prevotella and Porphyromonas spp.), anaerobic and microaerophillic streptococci, Propionibacterium spp., Eikenella corrodens, and Staphylococcus spp. However, intraoperative cultures of intracranial abscess cavities may yield no identiﬁable organism. In the majority of such cases, patients have received oral and/or parenteral antibiotics for the underlying sinusitis. There is often a correlation between the cultures obtained from the sinuses and from the intracranial abscess cavities (37,38). Nevertheless, in some patients the culture results do not correlate between the two sites (15,17). This is likely because of the different microenvironment of intracranial abscess cavities relative to the paranasal sinuses. Brook also suggests that variability in collection techniques, culturing for strict anaerobes, and improper specimen handling to prevent contamination may account for differences in the ﬁnal organism

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identiﬁcation (39). In some cases, however, the presence of sinusitis may be coincidental and not causative of the intracranial suppuration. Diagnosis Computed tomography can demonstrate cerebral abscess on the basis of low density attenuation of involved parenchyma and mass effect as well as the later development of ring-enhancement from collagen encapsulation of the necrosis. However, MRI can also demonstrate the early cerebritis phase of abscess formation. In addition, MRI T-1 weighted images can better demonstrate sulcus effacement and mass effect (22). Treatment Intracranial abscesses are usually treated by three complementary tactics: (1) immediate initiation of parenteral broad-spectrum antibiotic therapy (prior to neuro-imaging) with good blood–brain barrier traversal; (2) operative drainage of intracranial abscess; and (3) drainage of infected sinuses. The most commonly used empirical antibiotic choices include the combination of a third-generation cephalosporin (cefotaxime or ceftreaxone), a penicillinase-resistant penicillin, and metronidazole. Vancomycin may substitute the penicillinase-resistant penicillin to cover resistant S. pneumoniae. Subsequent antibiotic administration needs to be adjusted based on results from operative cultures. Intravenous antibiotics should be continued for four to eight weeks to maintain high CSF drug levels. As healing occurs and the blood–brain barrier is repaired, adequate drug levels will be achieved only with parenteral administration (15). A trial of antibiotic therapy alone may be warranted in a selected subset of patients who are deemed clinically stable (40,41). This group would include those in whom the risk of surgery is felt to be inordinately great, either because of the increased neurosurgical risk inherent in operating on deep, dominant, or multiple dispersed lesions or because of increased surgical risk from other health factors. Those patients with early, small abscesses may fall into this category as well, based on relative risk. Patients forgoing surgical drainage should be imaged at least weekly for the ﬁrst two weeks and bi-weekly through the eight-week course of antibiotic therapy. Clinical deterioration or lack of clinical improvement would necessitate reconsideration of surgical drainage. Sinus drainage may be performed by open technique or, more commonly, endoscopic technique and should follow intracranial drainage, but during the same course of anesthesia. Drainage procedures commence as soon as possible after localization of the purulent collection. Although small cerebral abscesses can be treated with a trial of antibiotic therapy, larger ones must be drained either with an open craniotomy or with CT-localized needle drainage procedures, depending on abscess location. Because of seizure risk attendant with cerebral abscess,

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prophylactic anticonvulsant therapy is warranted and should be initiated as soon as the diagnosis is established. Extra-axial Abscess (Subdural and Epidural Abscesses) Clinical Presentation Patients with subdural abscess, as with other intracranial infections, usually present with headaches, fever, and meningismus. Deterioration of neurologic status can progress rapidly, however, with decreased consciousness and development of seizures (42). Epidural abscess develops more insidiously, and symptoms may be nonspeciﬁc and overshadowed by the symptoms of the patient’s sinusitis (Fig. 4) Patients may not present for several weeks, until neurologic deterioration or seizures prompt CNS imaging (42). Bacteriology The bacteriology of subdural and epidural abscesses is similar to that previously described for intracerebral abscess (39).

Figure 4 Epidural empyema in a teenager being treated for sinusitis who presented to an emergency department because of new onset seizure.

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Diagnosis MRI is considered as the imaging modality of choice to diagnose both epidural and subdural suppurative collections because of its superior ability to detect abscess not evident on routine CT. In the event that MRI is unavailable or contraindicated, a contrasted CT scan can still reveal the diagnosis in most cases. Treatment Subdural pus collections are often loculated and extensive over the cerebral hemisphere and historically have required craniotomy. Multiple burr holes using CT stereotactic localization are now being employed more frequently (15). Epidural abscesses have also been traditionally treated with neurosurgical drainage. However, a more conservative approach has been suggested for small epidural abscesses, utilizing endoscopic or trephination for sinus drainage and intravenous antibiotics for six weeks. Heran et al. (21) used this approach on a group of four children with epidural abscess with a mean abscess size of 3 cm 3 cm 1 cm, without neurologic deﬁcits. Although two patients had transient worsening headache and fever over the ﬁrst 48 hours, there was no worsening on follow-up imaging, and patients improved over the subsequent two weeks without neurosurgical intervention. Antibiotic therapy was continued for six weeks. In some cases of epidural abscess with frontal sinusitis and osteomyelitis, exenteration of the frontal sinus (removal of anterior and posterior tables as well as obliteration of the nasofrontal recess) may be warranted (15). As with intracerebral abscess, drainage of involved sinuses should be coordinated with the neurosurgical procedures and antibiotic therapy should be initiated as soon as possible. Dural Sinus Thrombosis/Thrombophlebitis Clinical Presentation When complicating sinusitis, dural sinus thrombosis rarely occurs in isolation from other intracranial complications. On the other hand, isolated dural sinus thrombosis has myriad causes of which facial/head/neck infections account for only 8%. Patients with major venous sinus thrombosis often appear septic, with high fever, tachycardia, hypotension, and confusion. Headache is almost invariably present. Because of associated cerebral edema and ischemic and/or hemorrhagic infarction, both generalized and focal neurologic symptoms and signs are often present, including decreased or altered consciousness, seizures, paralysis, aphasia, and cranial nerve deﬁcits (26,43–45). In one study, patients who presented with more generalized neurologic impairment, suggesting intracranial hypertension, actually had more diffuse involvement of venous sinuses with thrombosis than did patients with a more focal presentation.

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Paradoxically, the patients with the intracranial hypertension presentation had better outcomes than those with focal neurologic impairment (43). In addition to fever and headache, eye signs will predominate early in the course of septic cavernous sinus thrombosis. As orbital venous congestion progresses, chemosis, periorbital edema, and proptosis can occur. Fundoscopy may reveal papilledema and retinal venous congestion. Ocular movement may become restricted by intraorbital edema and subsequently by oculomotor, trochlear, and abducens nerve palsies. The abducens nerve in particular may be affected early owing to its course within the cavernous sinus, and thus lateral nerve palsy may be noted. Although ocular ﬁndings are unilateral initially, progression to bilateral involvement occurs rapidly, usually within 48 hours (25,26). Bacteriology For cavernous sinus thrombophlebitis, the most common offending organism is S. aureus, accounting for two-thirds of cases (26,46). Other less common organisms include S. pneumoniae, gram-negative bacilli, and anaerobes (46). Diagnosis Venography can be used for diagnosing venous sinus thrombosis, but its use has largely been supplanted by contrasted MRI with venography (MRV). Contrasted CT scan can demonstrate ﬁlling defects within the venous sinus (25), if contraindication for MRI or MRI itself is unavailable. Occasionally the diagnosis is established in the operating room. Treatment For septic venous dural sinus thrombosis, management consists of medical therapy in conjunction with drainage of affected pneumatic sinuses and associated areas of intracranial purulence. In addition, anticoagulation has been advocated to facilitate antibiotic penetration, to decrease further propagation of septic thrombus, and to limit a precipitous rise in intracranial pressure. Others have argued that anticoagulation risks increased systemic or intracranial bleeding, including intraorbital bleeding and intracranial bleeding from cortical infarcts or from carotid rupture if the carotid has become infected in it course through the cavernous sinus. Of note, there have been only two cases of intracranial bleeding secondary to anticoagulation and septic cavernous sinus thrombosis (26,47) and no reported cases of intraorbital bleeding. There is also a theoretical risk of further propagation of intracranial infection secondary to a dispersal of septic emboli as the thrombus breaks down. However, in a small retrospective series of 31 patients with venous sinus thrombosis, Soleau and colleagues demonstrated that observation alone had the poorest results, with clinical improvement in only 2 of 5 patients and hemorrhagic complications in 4 of 5 with one death, whereas systemic

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anticoagulation resulted in improvement in 75% (8) of patients who were so treated, with no worsening of hemorrhage even in those patients with pretreatment hemorrhage; best results were obtained with a combination of mechanical endovascular clot dissolution and systemic anticoagulation, resulting in clinical improvement in 7 of 8 patients and one death. Chemical thrombolysis (urokinase or tissue plasminogen activator) was successful in restoring venous sinus patency in 6 of 10 patients, but at a signiﬁcant rate of fatal intracranial hemorrhage (30%) (45). These numbers must be considered in the context of the study limitations inherent with small study size and retrospective data collection. Options for anticoagulation include intravenous heparin and lowmolecular weight heparin, which may have a lower risk of bleeding but is less rapidly reversed. Once the patient becomes stabilized, conversion to oral anticoagulation can be undertaken. Although degree of anticoagulation has also not been deﬁnitively established, a general guideline would be essential to maintain an APTT ratio of 1.5 to 2.5 and an INR of 2.0 to 3.0 (26). Duration of anticoagulation should continue until follow-up neuroimaging conﬁrms dissolution of the thrombus, about several weeks; longterm anticoagulation is not required.

REFERENCES 1. Guillen A, Brell E, Cardona E, Claramunt E, Costa J. Pott’s puffy tumour: still not an eradicated entity. Child’s Nerv Syst 2001; 17:359–362. 2. Verbon A, Husni R, Gordon SM, Lavertu P, Keys TF. Pott’s puffy tumor due to Haemophilus inﬂuenzae: case report and review. Clin Infect Dis 1996; 23: 1305–1307. 3. Laine FJ, Smoker WR. The ostiomeatal unit and endoscopic surgery: anatomy, variation and imaging ﬁndings in inﬂammatory diseases. AJR 1992; 159: 849–857. 4. Clayman GL, Adams GL, Paugh DR, Koopman CF. Intracranial complications of paranasal sinusitis: a combined institutional review. Laryngoscope 1991; 101:234–239. 5. Younis RT, Lazar RH, Bustillo A, Anand VK. Orbital infection as a complication of sinusitis: are diagnostic and treatment trends changing?. Ear Nose Throat J 2002; 81:771–775. 6. Harris GJ. Subperiosteal abscess of the orbit. Age as a factor in the bacteriology and response to treatment. Ophthalmology 1994; 101:585–593. 7. Harris GJ, Bair RL. Anaerobic and aerobic isolates from a subperiosteal orbital abscess in a four year old. Arch Ophthalmol 1996; 114:98–100. 8. Brook I, Friedman EM, Rodriques WJ, Controni G. Complications of sinusitis in children. Pediatrics 1980; 66:568–572. 9. Chandler JR, Langenbrunner DJ, Stevens ER. The pathogenesis of orbital complications in acute sinusitis. Laryngoscope 1970; 80:1414–1428.

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10. Schwartz GR, Wright SW. Changing bacteriology of periorbital cellulitis. Ann Emerg Med 1996; 28:617–620. 11. Garcia GH, Harris GJ. Criteria for nonsurgical management of subperiosteal abscess of the orbit. Analysis of outcomes 1988–1998. Ophthalmology 2000; 107:1454–1458. 12. Uzeategui N, Warman R, Smith A, Howard CW. Clinical practice guidelines for the management of orbital cellulitis. J Pediatr Ophtalmol Strabismus 1998; 35:73–79. 13. Sobol SE, Marchand J, Tewﬁk TL, Manoukian JJ, Schloss MD. Orbital complications of sinusitis in children. J Otolaryngol 2002; 31:131–136. 14. Rahbar R, Robson CD, Petersen RA, DiCanzio J, Rosbe KW, Mcgill TJ. Management of orbital subperiosteal abscess in children. Arch Otolaryngol Head Neck Surg 2001; 127:281–286. 15. Gallagher RM, Gross CW, Phillips CD. Suppurative intracranial complications of sinusitis. Laryngoscope 1998; 108(11 Pt 1):1635–1642. 16. Giannoni CM, Stewart MG, Alford EL. Intracranial complications of sinusitis. Laryngoscope 1997; 107(7):863–867. 17. Giannoni C, Sulek M, Friedman EM. Intracranial complications of sinusitis: a pediatric series. Am J Rhinol 1998; 12(3):173–178. 18. Hytonen M, Atula T, Pitkaranta A. Complications of acute sinusitis in children. Acta Otolaryngol Suppl 2000; 543:154–157. 19. Ong YK, Tan HK. Suppurative intracranial complications of sinusitis in children. Int J Pediatr Otorhinolaryngol 2002; 66(1):49. 20. Albu S, Tomescu E, Bassam S, Merca Z. Intracranial complications of sinusitis. Acta Otorhinolaryngol Belg 2001; 55(4):265–272. 21. Heran NS, Steinbok P, Cochrane DD. Conservative neurosurgical management of intracranial epidural abscesses in children. Neurosurgery 2003; 53(4):893–897 (discussion 7–8). 22. Younis RT, Anand VK, Davidson B. The role of computed tomography and magnetic resonance imaging in patients with sinusitis with complications. Laryngoscope 2002; 112(2):224–229. 23. Younis RT, Lazar RH, Anand VK. Intracranial complications of sinusitis: a 15-year review of 39 cases. Ear Nose Throat J 2002; 81(9):636–638, 40–42, 44. 24. Bradley PJ, Manning KP, Shaw MD. Brain abscess secondary to paranasal sinusitis. J Laryngol Otol 1984; 98(7):719–725. 25. Amran M, Sidek DS, Hamzah M, Abdullah JM, Halim AS, Johari MR, Hitam WH, Ariff AR. Cavernous sinus thrombosis secondary to sinusitis. J Otolaryngol 2002; 31(3):165–169. 26. Bhatia K, Jones NS. Septic cavernous sinus thrombosis secondary to sinusitis: are anticoagulants indicated? A review of the literature. J Laryngol Otol 2002; 116(9):667–676. 27. Birck R, Krzossok S, Markowetz F, Schnulle P, van der Woude FJ, Braun C. Acetylcysteine for prevention of contrast nephropathy: meta-analysis. Lancet 2003; 362(9384):598–603. 28. Merten GJ, Burgess WP, Gray LV, Holleman JH, Roush TS, Kowalchuk GJ, Bersin RM, Van Moore A, Simonton CA, Rittase RA, Norton HJ, Kennedy TP. Prevention of contrast-induced nephropathy with sodium bicarbonate: a randomized controlled trial. JAMA 2004; 291(19):2328–2334.

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29. Younis RT, Anand VK, Childress C. Sinusitis complicated by meningitis: current management. Laryngoscope 2001; 111(8):1338–1342. 30. Clayman GL, Adams GL, Paugh DR, Koopmann CF Jr. Intracranial complications of paranasal sinusitis: a combined institutional review. Laryngoscope 1991; 101(3):234–239. 31. Archer BD. Computed tomography before lumbar puncture in acute meningitis: a review of the risks and beneﬁts. CMAJ 1993; 148(6):961–965. 32. Aronin SI, Peduzzi P, Quagliarello VJ. Community-acquired bacterial meningitis: risk stratiﬁcation for adverse clinical outcome and effect of antibiotic timing. Ann Intern Med 1998; 129(11):862–869. 33. Schuchat A, Robinson K, Wenger JD, Harrison LH, Farley M, Reingold AL, Lefkowitz L, Perkins BA. Bacterial meningitis in the United States in 1995. Active Surveillance Team. N Engl J Med 1997; 337(14):970–976. 34. de Gans J, van de Beek D. Dexamethasone in adults with bacterial meningitis. N Engl J Med 2002; 347(20):1549–1556. 35. van de Beek D, de Gans J, McIntyre P, Prasad K. Steroids in adults with acute bacterial meningitis: a systematic review. Lancet Infect Dis 2004; 4(3):139–143. 36. Quagliarello VJ, Scheld WM. Treatment of bacterial meningitis. N Engl J Med 1997; 336(10):708–716. 37. Brook I, Frazier EH. Microbiology of subperiosteal orbital abscess and associated maxillary sinusitis. Laryngoscope 1996; 106(8):1010–1013. 38. Brook I, Friedman EM, Rodriguez WJ, Controni G. Complications of sinusitis in children. Pediatrics 1980; 66(4):568–572. 39. Brook I. Aerobic and anaerobic bacteriology of intracranial abscesses. Pediatr Neurol 1992; 8(3):210–214. 40. Calfee DP, Wispelwey B. Brain abscess. Semin Neurol 2000; 20(3):353–360. 41. Rosenblum ML, Hoff JT, Norman D, Edwards MS, Berg BO. Nonoperative treatment of brain abscesses in selected high-risk patients. J Neurosurg 1980; 52(2):217–225. 42. Bockova J, Rigamonti D. Intracranial empyema. Pediatr Infect Dis J 2000; 19(8):735–737. 43. Bergui M, Bradac GB. Clinical picture of patients with cerebral venous thrombosis and patterns of dural sinus involvement. Cerebrovasc Dis 2003; 16(3):211–216. 44. Ferro JM, Canhao P, Stam J, Bousser MG, Barinagarrementeria F. Prognosis of cerebral vein and dural sinus thrombosis: results of the International Study on Cerebral Vein and Dural Sinus Thrombosis (ISCVT). Stroke 2004; 35(3): 664–670. 45. Soleau SW, Schmidt R, Stevens S, Osborn A, MacDonald JD. Extensive experience with dural sinus thrombosis. Neurosurgery 2003; 52(3):534–544 (discussion 42–44). 46. Ebright JR, Pace MT, Niazi AF. Septic thrombosis of the cavernous sinuses. Arch Intern Med 2001; 161(22):2671–2676. 47. Southwick FS, Richardson EP Jr, Swartz MN. Septic thrombosis of the dural venous sinuses. Medicine (Baltimore) 1986; 65(2):82–106. 48. Rosenfeld EA, Rowley AH. Infectious intracranial complications of sinusitis, other than meningitis, in children: 12-year review. Clin Infect Dis 1994; 18(5): 750–754.

SECTION V. SINUSITIS AND SPECIFIC DISEASES

14 Sinusitis and Asthma Frank S. Virant University of Washington, Seattle, Washington, U.S.A.

INTRODUCTION Sinusitis and asthma are commonly seen simultaneously in clinical practice (1–3). In fact, nearly 50% of asthmatics demonstrate upper airway symptoms and radiographic evidence of rhinosinusitis (4–11). Chronic sinusitis and asthma share several pathophysiological features: chemical mediators, e.g., histamine, cysteinyl leukotrienes, and prostaglandin D2; cytokines, e.g., interleukin-4 (IL-4), IL-5, IL-9, IL-13, and CCL11 (eotaxin); and cellular mediators, principally eosinophils and TH2 lymphocytes (12–14). These observations have led to the concept of ‘‘one airway . . . one disease’’ rather than the idea of isolated upper and lower airway disorders. At the same time, numerous clinical studies have demonstrated that aggressive medical or surgical treatment of sinusitis improves asthma, suggesting that upper airway inﬂammation may actually have a causative role in lower airway disease. This chapter will explore the historical association of sinusitis and asthma, the common inﬂammatory basis of these disorders, and evidence that sinus therapy can improve concomitant asthma. A brief discussion of possible mechanisms by which sinusitis could exacerbate asthma is followed by implications for patient management. HISTORICAL ASSOCIATION OF SINUSITIS AND ASTHMA About two millennia ago, it was Galen’s belief that sinusitis caused asthma; this assertion was based on the notion that abnormal secretions dripped 291

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from the skull into the lungs, inducing irritation and wheezing. This idea was generally embraced, leading to nasal irrigation and purging to help treat asthma. Ironically, this notion was abandoned in the mid-1600s when early anatomists demonstrated that no direct connection between the skull and lungs existed (15). Interest in the association between sinusitis and asthma was revived in 1870 when Kratchmer showed that chemical irritation of animal upper airways with ether, cigarette smoke, or sulfur dioxide caused bronchoconstriction (16). At the beginning of the twentieth century, Dixon and Brodie also demonstrated that nasal mechanical or electrical stimuli could induce reﬂex lower airway obstruction (17). Clinical observations early in the twentieth century reafﬁrmed that upper and lower airway diseases were frequently coexistent. Gottlieb observed that 31 of 117 adult asthmatics also had clinical evidence of sinusitis (4). Chobot and Weille (5,6) reported that sinus symptoms were present in as many as 72% of children and adults with asthma. Bullen’s review of 400 sinusitis patients revealed a 12% incidence of asthma with many noting that sinus symptoms preceded the appearance of their asthma (18). Over the last three decades, several studies in adults and children demonstrated that 21 to 31% of asthmatics have signiﬁcantly abnormal sinus radiographs (mucosal thickening >5 mm, air–ﬂuid levels, or opaciﬁcation) (7–9,19). In contrast, only 5 to 6% of asymptomatic adults and children showed such radiographic sinus changes (20,21). Collectively, these reports suggest that asthmatics are four to six times more likely to display sinus pathology than healthy non-asthmatics—strong evidence of an association between these diseases. CHEMICAL, CYTOKINE, AND CELLULAR MEDIATORS OF AIRWAY DISEASE Further evidence of a relationship between sinusitis and asthma is apparent after comparing chemical, cytokine, and cellular mediators in these diseases (Table 1). Chemical Mediators Levels of histamine, prostaglandin D2, and the cysteinyl leukotrienes (LTC4, LTD4, and LTE4) are all elevated in the maxillary sinuses of patients with chronic eosinophilic sinusitis and in the bronchoalveolar lavage ﬂuid of patients with asthma (12–14,22). Cytokine Mediators Both chronic sinusitis and asthma may demonstrate a variety of common cytokine mediators, including IL-4, IL-5, IL-9, IL-13, CCL11 (eotaxin),

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Table 1 Chemical, Cytokine, and Cellular Mediators of Airway Disease Type Chemical

Mediator Histamine Prostaglandin D2 Leukotriene C4, D4, E4

Cytokine

Cellular

Interleukin 4 Interleukin 5 Interleukin 9 Interleukin 13 CCL 11 (eotaxin) Tumor necrosis factor a Eosinophils TH2 lymphocytesa

Effector functions Vasodilation, hypersecretion, bronchoconstriction Smooth muscle constriction Vasodilation, hypersecretion, bronchoconstriction Directs B cell to produce speciﬁc IgE Clonal growth factor for eosinophils T cell, mast cell growth factor Augments speciﬁc IgE secretion Chemoattractant for eosinophils Augments inﬂammation (fever, pain) Inﬂammation, airway hyperresponsiveness Produce/release IL-4, IL-5, IL-9, IL-13

a

TH2 lymphocytes are a major mediator in allergic rhinosinusitis and allergic asthma; these cells are a less signiﬁcant component in non-allergic airway inﬂammation.

and TNF-a. In patients with underlying allergic disease, all of these mediators are present throughout the airway; in non-allergic eosinophilic airway disease, IL-5, eotaxin, and TNF-a are predominating features (23–26). Cellular Mediators Almost 80 years ago, Hansel (27) remarked on the histological similarities between chronic sinusitis and persistent asthma: marked eosinophilia, glandular hyperplasia, and stromal edema. More recently, Harlin and coworkers examined the role of the eosinophil in the induction of chronic sinusitis. They examined sinus tissue for the presence of eosinophils and/or major basic protein (MBP—a signiﬁcant eosinophil-derived granule protein) in 26 adolescent and adult patients with chronic sinusitis. All 13 sinus samples from asthmatics and six of seven samples from allergic rhinitis patients showed signiﬁcant eosinophils and MBP while none of the six patients with chronic sinusitis without asthma or allergic rhinitis showed signiﬁcant tissue eosinophils (one had MBP) (28). Hisamatsu and colleagues (29) showed that MBP at physiologic concentrations in vitro could cause epithelial damage and ciliary dysmotility in sinus mucosal tissue. They concluded that eosinophils could play an important role in increasing the risk for bacterial sinusitis and in the induction of nasal hyperresponsiveness through cholinergic pathways. Potentially, this effect of upper airway eosinophils could also affect bronchial hyperresponsiveness through the same neural pathways (30).

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IMPACT OF MEDICAL SINUS THERAPY ON ASTHMA Over the last two decades, several groups have studied the effect of medical treatment for sinusitis in children with asthma (31). Businco et al. (32) studied 55 asthmatic children with mild to severe maxillary sinus thickening. After 30 days therapy with either nasal corticosteroid plus antihistamine/ decongestant or ampicillin plus antihistamine/decongestant, all children showed decreased asthma severity and sinus radiographic improvement. In 1983, Cummings and coworkers compared antibiotics plus nasal corticosteroids and decongestants versus placebo in the treatment of asthmatic children with opaciﬁed or markedly thickened maxillary sinuses. Although pulmonary function and bronchial hyperresponsiveness were not signiﬁcantly changed in either group, the children on active treatment had reduced asthma symptoms and less need for bronchodilators and oral corticosteroids (33). The next year, Rachelefsky et al. (34) treated 48 children who had at least a three-month history of sinusitis and asthma; treatment included prolonged antibiotics and, in select cases, antral lavage. Nearly 80% of the subjects were able to discontinue bronchodilators and more than 50% returned to normal lung function. Independently in 1984, Friedman and colleagues followed the effect of antibiotic treatment in eight children with acute sinusitis and asthma exacerbation; seven of the children showed signiﬁcant improvement in asthma symptoms. Although pulmonary function did not statistically improve, response to bronchodilator doubled compared with pre-study levels (35). More recently, Oliveira studied 46 allergic and 20 non-allergic children with sinusitis and asthma. Therapy included 21 days of antibiotics, antihistamines, decongestants, nasal saline irrigation, and ﬁve days of oral corticosteroids. By the end of the study, only the children who demonstrated radiographic resolution of their sinusitis had improved pulmonary function and bronchial hyperresponsiveness (36). Additional evidence that upper airway inﬂammation can affect lower airway disease comes from Corren’s research on patients with seasonal allergic rhinitis/bronchial hyperresponsiveness; seasonal nasal corticosteroid treatment alone could prevent increased bronchial hyperresponsiveness (37,38). IMPACT OF SURGICAL SINUS THERAPY ON ASTHMA In contrast to medical treatment, the impact of sinus surgical intervention on asthma is variable (39). In 1920, Van der Veer published his clinical observations that asthma was worsened by sinonasal surgery (40). Nearly a decade later, Francis published a series of 13 patients with surgical intervention for chronic sinusitis; nine demonstrated worsening of their lung symptoms after operation (41). In contrast, Weille’s 1936 study of 500 asthmatics revealed a 72% incidence of sinusitis. Ultimately, over half of the 100 subjects who had sinus

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surgery experienced an improvement in asthma. Ten became totally asymptomatic. At the same time, over 40% of the sinusitis patients who did not have surgery also had asthma improvement (6). Davison’s study in 1969 observed that all but one of his 24 patients had at least a 75% improvement in asthma symptoms after sinus drainage (42). In the early 1980s, Slavin and coworkers described similar results in 33 adult sinus surgical patients: 85% had signiﬁcantly better asthma control and were able to markedly reduce their requirement for oral corticosteroids (43). Over a period of months, though, 40% of those who initially experienced improvement following surgery demonstrated asthma exacerbations. Werth reported on 22 children with chronic sinusitis and asthma in 1984; asthma markedly improved in 20 after sinus surgery (44). The same year, Juntunen et al. described 15 children with persistent chronic sinusitis despite inferior meatal antrostomy and adenoidectomy; even this degree of surgical intervention appeared to improve asthma symptoms and lung function (45). The last decade has spawned numerous additional studies, primarily, though not exclusively, in adults with nasal/sinus polyps; uniformly, endoscopic sinus surgical intervention improved asthma (46–52).

SINUSITIS AS A TRIGGER FOR ASTHMA—MECHANISMS Nearly 80 years ago, Gottlieb suggested several ways in which sinusitis might excerbate asthma (Table 2): neural reﬂexes pathways, nasal obstruction, sinus inﬂammatory secretions draining into the lower airway, and indirect delivery of inﬂammatory ‘‘signals’’ through the systemic circulation (4). Recently other researchers have suggested decreased b-adrenergic responsiveness as an additional possible mechanism (30,35). Although controversies remain, the actual process in individual patients is probably a combination of one or more mechanisms (53). Neural Reflex Pathways In the early twentieth century, Sluder proposed that asthma was caused by reﬂexes intiated in the nose and sinuses (54). Subsequent animal research

Table 2 Sinusitis as a Trigger for Asthma––Mechanisms Neural reﬂex pathways: trigeminal afferents ! CNS ! vagal efferents Nasal obstruction: decreased air ﬁltration, humidiﬁcation, heating Sinus inﬂammatory secretions draining to lower airway: direct effect Sinus inﬂammatory mediators exerts systemic effect on lungs: indirect effect Sinusitis reduces b-adrenergic responsiveness: unknown pathway

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after upper airway ‘‘irritation’’ yielded controversial results, including no change in lower airway resistance, bronchodilation, and bronchoconstriction. In 1969, Kaufman et al. (55) studied non-asthmatics with tic doloreux, inducing increased lower airway resistance by delivering silica into the upper airway. After surgical treatment of tic doloreux with trigeminal nerve resection, this response was blocked, leading the authors to postulate a ‘‘nasalbronchial reﬂex’’ mediated through trigeminal afferents and vagal efferents. Other groups demonstrated that nasal provocation with cold air, sulfur dioxide, or petrolatum could also induce pulmonary resistance changes after exposure (56–58). Salome demonstrated that histamine nasal challenge in symptomatic perennial allergic rhinitis patients could induce at least a 10% decrease in forced expiratory volume in one second (FEV1) (59). Three other studies on asymptomatic seasonal allergic patients failed to show such a change, suggesting that baseline nasal inﬂammation was important for this response (60–62). Corren and coworkers evaluated 10 patients with a previous history of asthma exacerbation during periods of seasonal allergic rhinitis (37). Although spirometry was stable, lower airway methacholine responsiveness increased 30 minutes after nasal radionuclide-labeled nasal antigen challenge—an effect which lasted for 4 hours. A neural mechanism is suggested by the rapidity of this change and veriﬁcation that antigen did not reach the lower airway. A decade ago, Brugman et al. (63) studied this issue in rabbits. After the induction of sterile sinus inﬂammation, they also found no change in lung function but did note increased bronchial responsiveness to histamine. It appeared that these changes could be blocked by preventing inﬂammatory exudate from progressing beyond the larynx, suggesting that direct deposition of mediators into the lungs was an important mechanism for this effect. Bronchial lavage in ‘‘positive reactor’’ rabbits failed to show histologic signs of inﬂammation, however, again raising the possibility of a neural pathway. Nasal Obstruction Nasal/sinus edema and increased purulent secretions lead to nasal obstruction in patients with rhinosinusitis. This is probably an important mechanism for asthma exacerbation in these patients since several important nasal functions may be bypassed: ﬁltration, humidiﬁcation, and warming of inspired air (64). When this occurs, the patient is at risk for increased lower airway exposure to allergen, irritants, dry air, and cold air—all known triggers for asthma. Sinus Inflammatory Secretions Draining to Lower Airway Based on studies nearly a century ago, clinicians speculated that inﬂammatory material from the upper airway could directly drain into the lower

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airway and cause symptoms (4–6,18). In recent years, Huxley (65) showed that nearly 50% of subjects would aspirate upper airway material (radiolabeled) into the lung during sleep or depressed consciousness. This conclusion was criticized because most aspirators had artiﬁcially induced subconsciousness and perhaps simply could not clear their pharynx normally. A similar subsequent study by Winﬁeld failed to show signiﬁcant aspiration episodes (66). Bardin et al. (67) examined the pathway of radiolabeled particles placed in the maxillary sinuses of 13 chronic sinusitis patients (nine with asthma). Although radioactive particles were observed in the nose, sinuses, pharynx, and esophagus, no material could be seen in the lower airway. Collectively, these studies suggest that direct aspiration of inﬂammatory drainage into the lungs is a minor mechanism for asthma at best. Sinus Inflammatory Mediators Exerting Systemic Effect on Lungs Bronchial provocation in asthmatics causes an increase in systemic chemotactic factors and it is known that lower airway disease is more common in patients with systemic inﬂammatory disorders (68,69). Together, these studies suggest the possibility that sinus inﬂammatory mediators could induce asthma through systemic pathways. Results from the Brugman study, however, seem to suggest this is unlikely (63). When the rabbits were placed so that inﬂammatory drainage could not progress past the larynx, lower airway hyperresponsiveness was not observed. Since the degree of sinus inﬂammation was similar in all test rabbits (despite positioning), it would be anticipated that any systemic mediator effects should also be consistent (and all rabbits would show an effect). Results suggest that if present, a systemic pathway alone is not adequate to enhance bronchial responsiveness. Sinusitis Reduces b-Adrenergic Responsiveness Friedman et al. (35) observed that asthmatics demonstrated increased response to b-adrenergic medication after their sinusitis was successfully treated. The authors speculated that sinusitis might somehow reduce overall airway b-adrenergic responsiveness, possibly down-regulating receptors. This could be a spurious effect and simply due to an increased use of b-adrenergic medication in active asthma (a known down-regulator of b-receptors). This postulated mechanism remains a conjecture until further appropriate b-adrenergic receptor studies can be performed. CLINICAL IMPLICATIONS Given the association between sinusitis and asthma, it is important to consider both diseases, even when the patient history and complaints focus only on a single entity (Fig. 1).

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Figure 1 Association between sinusitis and asthma.

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Evaluation of Chronic Sinusitis When the clinical diagnosis of sinusitis is made, careful attention should be directed to the history of cough, dyspnea, or overt wheezing. If any of these symptoms is present, lung function should be measured (peak expiratory ﬂow rate or spirometry). The importance of even subtle lung function abnormalities can be conﬁrmed by measuring the response to a bronchdilator—signiﬁcant improvement reﬂects bronchial hyperresponsiveness. Some patients with refractory chronic sinusitis demonstrate persistent cough and normal lung function. In this setting, a bronchial methacholine challenge can assess whether a component of the patient’s cough is due to bronchial hyperresponsiveness (and thus would respond to appropriate medications). Evaluation of Chronic Asthma Sinusitis should always be considered as an important trigger for asthma exacerbation. The history is examined for a recent prolonged upper respiratory tract infection (URTI) (beyond 10 to 14 days), particularly with nasal congestion and cough. In this setting, nocturnal cough, especially to the point of vomiting, is suggestive of sinusitis in a child. Supportive evidence for sinusitis includes nasal cytology with predominance of neutrophils and radiographic evidence for signiﬁcant sinus inﬂammation (opaciﬁcation, air–ﬂuid level, or mucosal thickening of greater than 50% of the sinus volume); these ﬁndings are only speciﬁc in the context of a clinical history of prolonged URTI. In children, a Waters’ view radiograph is often a useful screen because it can be easily obtained, is inexpensive, and nearly all new cases of sinusitis will have a maxillary component. In older patients or when isolated ethmoid disease is suspected, a coronal sinus CT is more sensitive (70). Aggressive treatment of suspected bacterial sinusitis includes appropriate antibiotics (based on likely causative microorganisms) and adjunctive therapy to enhance ostial drainage, e.g., nasal saline, decongestants, and corticosteroids. Saline lavage and decongestants can be useful, particularly early in the course of treatment, to aid in symptom relief and promote mucociliary clearance. Nasal and, in severe cases, oral corticosteroids are a crucial part of treatment in the setting of associated underlying eosinophilic rhinitis (allergic or non-allergic) and asthma. In addition to reducing upper airway edema and purulent rhinorrhea, corticosteroids reduce nasal and associated bronchial hyperresponsiveness. Prevention of Disease in Patients with Sinusitis and Asthma When presented with acute sinusitis and asthma, the clinician’s ﬁrst goal is to normalize the sinuses because this alone will improve the lower airway disease. Once stable, prevention starts with exploring the possibility of underlying rhinitis. A baseline evaluation should include nasal cytology to

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quantify the degree of inﬂammation when stable, and appropriate skin testing to determine allergic triggers. A long-term approach to prevention begins with environmental control for relevant indoor allergens, e.g., dust mites, animal danders, or molds. If the underlying rhinitis is mild, addition of nasal corticosteroids and possibly leukotriene receptor antagonists during URTIs can often provide a critical reduction in sinus